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100+ Essential CRO Terms to Help You Conquer Conversion

Keeping abreast of conversion optimization trends and technologies can be tiring. Even more so when the terms/keywords used by conversion experts are going over your head.

This post aims to help you by bringing all popular CRO terms — basic as well as advanced — at one place.

To make the list comprehensive, the terms have been compiled from a wide range of conversion optimization disciplines such as A/B testing, Website Design, Online Ads, SEO, and more.

(Note: The following terms have been defined in context of CRO)

You can click one of the letters below to directly reach the letter you want.

A    B    C    D    E    F    G    H    I    L    M    N    O    P    R    S    T    U    V    W


A/B TESTING (SPLIT TESTING): It is an experiment where two versions of a web page are compared to see which one produces more conversions.

A/B testing
Graphical representation of an A/B test

Here is a complete guide that tells you all about ‘Why to A/B test?’ and ‘What to A/B test?’

ABOVE THE FOLD: It is the portion of a web page that is visible without scrolling.

It is advisable to display a website’s offering and differentiators above the fold.

Related Post: This is how a website leveraged above-the-fold space to boost customer engagement.

AFFILIATE: It is a website that promotes another company’s products or services on its space, and earns commission from it.

This practice is known as Affiliate Marketing.

ALT TEXT: It is an HTML tag, where description of an image (or any other multimedia) can be inserted.

For instance, when a visitor chooses ‘don’t display images’ for a website, the alt-text of an image is shown in place of the image.

ANCHOR TEXT: It is the clickable text on a hyperlink.

Best practices for SEO advise that anchor text should be closely related to the web page it links to.

AUTHORITY SITE: The websites that search engines consider to be of high-quality, are called authority sites.

AOV: It is an acronym for Average Order Value. As the name suggests, it is the average value (typically in dollars) of all orders processed by an eCommerce store.



BACKLINK: It is also known as an inbound link. Suppose website A contains a hyperlink that directs to website B. For website B, that hyperlink is a backlink.

A website having backlinks from authority sites will rank better in search engine results. Tweet: Glossary of 100 Conversion Optimization terms. Find at

BANNERS: They are rectangular segments (of various dimensions) on a website that are generally used to display ads.

These are some of the typical banner sizes used across the web:

web banner sizes

BANNER BLINDNESS: It is a phenomenon where website visitors consciously or subconsciously ignore banner ads or any other banner-like graphic on a website.

BASELINE: Baseline conversion rate is the existing conversion rate of a website, which an A/B test attempts to improve.

BAYESIAN: Bayesian is a probability concept which interprets probability as a degree of belief.

In A/B testing, bayesian probability offers an absolute level of a test result’s validity.

BEHAVIORAL TARGETING: It is an advertising strategy where websites present their visitors with ads that are specifically related to their interests and preferences.

Websites do this by tracking a visitor’s shopping and browsing history.

BELOW THE FOLD: It is the portion of a website that is not above the fold.

BOUNCE: When a visitor arrives on a website and leaves without viewing other pages on the website, it is called a bounce.

BOUNCE RATE: It is the percentage of visitors that end up bouncing from a website.

It is often used as a measure to check a website’s effectiveness.

A website’s higher bounce rate reflects its lack of ability to engage visitors. Tweet: Glossary of 100 Conversion Optimization terms. Find at

BREADCRUMB NAVIGATION: It is a set of navigation links on a web page that tells the exact location of the web page in a website.

This is how Flipkart, an eCommerce store, uses breadcrumb navigation on its website.

breadcrumb navigation




CALL TO ACTION (CTA): A Call to Action is an instruction given to website visitors that provokes an immediate response.

Any action that a website wants its visitors to perform is carried out using a CTA button.

A CTA button is the doorway to conversions. Tweet: Glossary of 100 Conversion Optimization terms. Find at

And hence, it is one of the hottest website elements that is A/B tested.

Related Post: Read this interesting case study about an A/B test involving CTA variations.

CANONICAL URL: If there are multiple URLs through which a web page can be reached (like and, search engine picks up the preferred URL defined by the webmaster.

This preferred URL is know as a canonical URL.

Want to read more on it? You can start with this fine article on canonicalization from Moz.

CART ABANDONMENT: Cart abandonment occurs when eCommerce website visitors initiate the purchase process of a product but don’t buy it at the end.

It is one of the biggest pain areas for eCommerce players.

However, cart abandonment can be alleviated using certain onsite practices.

One of those practices is ‘Website Checkout Optimization’. This infographic illustrates how to do it.

CHURN RATE (ATTRITION RATE): It is the percentage of customers of a service that discontinue to use the service in a specific interval of time.

A high churn rate often indicates that a company’s services are not satisfactory.

CLICKBAIT: It refers to the sensationalized low-quality content on the internet, whose main purpose is to attract visitors and generate revenue from ad clicks.

Below is an example of clickbait content.

clickbait example

CLICK TO CALL: It is a CTA button on a mobile website/application that allows visitors to directly call a phone number.

CLICKMAP: Clickmap shows the number of clicks for each link on a website.

CLICKSTREAM: It is the list of links that a visitor clicked on, during their stay on a website.

Clickstream is used to determine the interests and site preferences of a visitor.

CLICKTHROUGH RATE (CTR): It is the percentage of clicks on a button or a link, out of the total number of visitors who saw it.

CTR is used to determine the success rate of a campaign or a web page.

CLICKTHROUGH PAGE: It is a web page that is placed before a website’s main action-page (like a shopping cart page for an eCommerce website).

Its purpose is to prepare visitors for a conversion on the next page.

CLOAKING: Content cloaking is the act of showing different content to search engine bots and actual human visitors.

CONFIDENCE LEVEL: It is the probability that a variation in an A/B test won not because of chance.

CONFIDENCE INTERVAL: The range in which the result of an A/B test lies is known as confidence level.

CONTENT MANAGEMENT SYSTEM: It is a web-based application that allows people to easily (without any coding involved) add/update text and multimedia content on a website.

CONTENT MARKETING: It’s the practice of creating and popularizing text and multimedia content for a business to attract and retain customers.

CONTROL PAGE: It is the website’s existing page that is pitted against its variation(s) in an A/B test.


CONVERSION: It is the action that marketers want a website visitor to take.

Newsletter signups, account registrations, and product enquiries are generally considered as micro-conversions.

A monetary transaction is generally considered as a macro-conversion.

CONVERSION RATE: It is the percentage of visitors who have completed a conversion.

CONVERSION RATE OPTIMIZATION (CRO): It is the practice of continually improving a website’s ability to effect conversions.

COOKIES: Cookies are small files that are stored within a web browser of a computer. Cookies have information related to a user’s visit to specific websites.

Cookies are used to track users’ browsing history and site preferences.

Website cookies funny image

COST PER ACQUISITION: It is the total cost of converting a website visitor into a paying customer.

COST PER CLICK (CPC): It is a payment model for online ad campaigns.

CPC is the amount that an ad owner pays every time when a visitor clicks on their ad.

CPM: It can be extended to Cost per Thousand Impressions. CPM is the amount that an ad owner pays when the ad is displayed for a thousand times.

CRAWLERS (SPIDERS): A web crawler is an internet bot that browses the entire world wide web and indexes websites into a directory.

CRM System: CRM is an acronym for Customer Relationship Management.

A CRM System is an enterprise software that contains the history of company’s interaction with all its customers via multiple channels.

CROSS-SELL: It is the act of selling complementary products to existing customers.

Cross-sell example

It is a popular practice among marketers because selling to an existing customer is a lot easier than selling to a new prospect.

Related Post: Learn how Upselling and Cross-selling can boost eCommerce revenue.



DIRECTIONAL CUES: Visual elements of a website that are used to direct visitors’ attention to a specific area on the website (a CTA or an information box) are known as directional cues.

Related Post: By optimizing directional cues towards its CTA button, a company achieved 8% increase in conversions.

DYNAMIC CONTENT: When a website serves distinct content to different visitors (based on their demographic attributes), the content is referred to as dynamic content.



EMAIL MARKETING: It is a practice where businesses use email as a medium to nurture their leads and retain their customers.

Sending personalized and value-packed emails help push conversions.

EXIT POPUP: It is a popup that well, pops up on the screens of website visitors as soon as they show an intent to leave the website.

Exit popups generally carry some sort of incentive for visitors, encouraging them to engage more with the website.

This is an exit popup that VWO used for one of its campaign:

Exit popup
(Click on the image if you want learn these principles)

EXIT SURVEY: It is a small set of questions that ask visitors about their website experience, when they try to leave the website.

EYE FLOW: It is the study of visitors’ eye movement while browsing a website.

Eye flow helps to track areas that visitors view or discard the most.



FORM TESTING: When forms on a website are A/B tested, it is referred to as form testing.

FRICTION: Friction is caused by elements of a website that confuse or distract visitors, resulting in a loss of conversions.

Friction-causing website elements can be complex navigation links, cluttered boxes, CTAs with lack of visual contrast, etc.

FUNNEL: Conversion funnel is a marketing model that illustrates all steps taken by a customer towards purchasing a product from a website.

FUNNEL TESTING: Funnel testing involves executing A/B tests across all web pages of a website funnel.

Related Resource: Find out how VWO lets you do funnel testing with ease.



GAMIFICATION: It is the practice of introducing game-style offers to potential/existent customers.

The idea is to encourage them to complete more transactions — in a fun and engaging way.

For example, Loyalty programs is a gamification strategy.

GEO-FENCING: It is the practice of targeting users based on their location.

It involves using GPS/map technology to create a virtual boundary around a physical location, and sending targeted messages to users when they enter the area.

GROWTH HACKING: It is the use of low-cost and innovative marketing techniques combined with search engine optimization, website analytics, content marketing, and A/B testing to increase a business’ popularity and conversions.



HEATMAP: Heatmap is a graphical representation of most-clicked areas of a website.

A typical heatmap looks like this:

Heatmap example

Related Resource: Create your own website’s heatmap, using VWO’s heatmap tool.

HERO IMAGE: It is the most prominent banner or image present on a website.

Hero image is usually the first visual of a website that visitors encounter.




IMPRESSIONS: The number of times an ad is displayed to online visitors is counted as impressions.

INTERRUPTION: It is a practice of providing attention-grabbing content to website visitors that purposely breaks their usual website navigation experience.

Exit popups can be considered as a form of interruption.



LANDING PAGE: It is the web page that visitors are directed to when they click on an ad (or a link from a campaign).

A landing page can be a lead generation page or a clickthrough page.

The possibility of a conversion depends heavily on the quality of a landing page. Tweet: Glossary of 100 Conversion Optimization terms. Find at

Related Resource: Use this free tool by VWO to test the effectiveness of your landing page.

LATENT CONVERSION: When visitors complete a conversion on their follow-up visit to a webpage (and not on the first visit itself), it is known as a latent conversion.

LEADS: They are potential customers for a business who have already shown interest by providing their contact information — permitting the company to contact them.

LIFETIME VALUE: It is the total profit that a business is expected to earn from a customer over their entire future relationship with the company.

LINK BUILDING: It the process of earning more backlinks to a website.

LIVE CHAT: It is a real-time chat-based customer support service that websites provide to their visitors.

LONG TAIL KEYWORDS: These are search phrases that usually include more than three words. Long tail keywords describe a search query comprehensively.



META TAG: It is an HTML tag that allows webmasters to insert text description of a web page.
The meta description for web pages appear with their links in search engine results.

The image below illustrates how meta description of a link is included in search engine results:

meta description on SERP

MICROSITE: It is a small website — usually different from a company’s main website — that has succinct content and is related to a specific campaign.

MULTIVARIATE TESTING: When multiple variations of a webpage are tested — for more than one element — to determine the version offering the highest conversions, it is known as multivariate testing.

Related Post: This case study demonstrates how multivariate testing can result in higher conversions.



NULL HYPOTHESIS: The hypothesis that an A/B test tries to disprove is called null hypothesis.

The null hypothesis states that the conversion rates of control and variation(s) are the same.



ORGANIC: The traffic coming to a website through non-paid search engines results is called organic traffic.

OUTBOUND LINKS: The hyperlinks that a website uses to direct visitors to other websites, are called outbound links.



PERSONALIZATION: It is the practice of customizing web pages (or any other digital content) to individual visitors’ interests or preferences.

PROXIMITY: It is a web designing practice that directs a webmaster to group similar or related website elements together, and place unrelated or dissimilar elements apart.



RESPONSIVE WEBSITE DESIGN (RWD): A website with responsive design adapts its layout to that of the viewing environment (mobile, desktop or tablet) to provide an optimum viewing experience to visitors.

Below is a basic graphical representation of a responsive website.

Responsive website design

RETARGETING: When website visitors are shown ads/banners about the things they earlier browsed but didn’t convert, it is known as retargeting.

Retargeting is used to push those visitors for a conversion who have already shown some interest in the website.

REVENUE PER VISITOR (RPV): It is the average revenue that a website earns from each of its visitors.

RPV is considered as the most appropriate metric that is used to measure an eCommerce store’s performance. Find out why.



SAMPLE SIZE: Sample size in A/B testing is the set of visitors that determine the conversion rate of different variations of a website.

SCARCITY: It is a psychological tactic that marketers use to push visitors towards a conversion. Scarcity takes advantage of the human fear of ‘shortage’.

“Only 5 items left” and “Sale only till 8 PM” are some instances where scarcity marketing is used.

SERPs: It is an acronym for Search engine Result Pages.

The ultimate goal of SEO strategies is to make websites appear on the top of a SERP.

Below is an example of an SERP:

SERP - Search Engine Results Page

SITEMAP: It is a list of all web pages within a website, displayed in a hierarchical manner.

SOCIAL PROOF: Customer testimonials, product reviews and trust badges make up the social proof of a website.

A few social proof elements have been highlighted in the screenshot below:

Landing Page Image Outperforms Video, Increases Monthly Revenue by $106000 2015-08-03 16-17-00

Visitors trust a website more when they are presented with social proof. Tweet: Glossary of 100 Conversion Optimization terms. Find at

Related Post: Find out how a website performed better with social proof elements.

SPLIT TESTING: It is an umbrella term that covers both A/B testing and Split URL testing.

Related Resource: Know how Split testing improves your website’s performance.

SPLIT-URL TESTING: It involves testing multiple versions of a webpage that are hosted on different URLs.

Split URL testing is best suited when there are major design changes on the web page.

STANDARD ERROR: The degree to which the result of an A/B test can be apart from the actual figure is called standard error.

STATISTICAL SIGNIFICANCE: Statistical significance determines the validity of an A/B test.

Related Resource: Find out the significance of your A/B test results, using VWO’s free statistical significance calculator.



TEST HYPOTHESIS: It is a tentative assumption that changing a specific element(s) of a website will lead to higher number of conversions.

Establishing a test hypothesis is the first step towards executing an A/B test.

TITLE TAG: It is an HTML tag — a part of meta tags — that defines the title of a web page.

A web page’s title tag is displayed above its meta description in SERPs.

TRUST BADGES: Trust badges are small logos or icons that convince visitors about the safety and credibility of the website.

These are a few popular trust badges across the internet:

Trust badges

Related Post: Check out how adding trust badges improved conversions for a website.

TEST DURATION: It is the specific time period over which an A/B test is run.

It is imperative to determine the minimum test duration of an A/B test for reaching a conclusive result.

Related Resource: Unsure about how long to run your A/B test? Use this free tool by VWO.



UNIQUE VISITORS:  It is the number of distinct visitors of a website out of its total traffic.

Unique visitors are tracked using cookies.

UPSELL: It is a practice of offering a higher value (and usually more expensive) product/service to an existing customer.


USABILITY:  It refers to the ease of use of a website.

The usability of a website can be tested by hired experts, who thoroughly analyze the website and provide suggestions for improvement.

Related Post: Check out the detailed usability review of

USER GENERATED CONTENT (UGC): It is content in the form of text, images and videos that is submitted by users to a website as a part of some campaign.

This was one of the UGC campaigns run by Universal:

ugc campaign

Here is an interesting post on 10 effective UGC campaigns by Hubspot.

USER INTENT: It is the end goal that a user wants to fulfill through submitting queries on search engines.

Understanding the user intent is imperative for ranking well in search engines.

This is how the focus in SEO is changing from keywords to user intent.

USER TESTING: When the usability of a website is tested with the help of real people, it is called user testing.

User testing can be done in the following ways:

  1. By inviting potential users to use your website, and observing the problem areas in usability.
  2. By evaluating a website based on the behavior of real visitors — using tools like clickmaps and heatmaps. (The users are not aware that their website usage is being tracked for analysis.)



VARIABLE (VARIATION): In A/B testing, variable is the challenger web page that is pitted against the control.



WEBMASTER: The person who is responsible for maintaining a website is called a webmaster.

WHITESPACE: It is a design strategy which involves using blank spaces for directing attention towards a valuable website element such as a CTA.

What can be a better example of the use of whitespace design than this:

Google 2015-07-31 18-38-06

WIDGETS: They are small application boxes that typically fit in one of the side banner areas of a website.

The use of widgets vary in a range of functions like providing navigation links, submission of forms, and more.

In fact, you can see widgets on the right side of your desktop screen right now.

Use this glossary to move one step closer towards becoming a CRO expert. If you have any other terms to add to the list, please post it on the comments section below.


Nitin is a traveler, a cinephile, and a webaholic. (He just can't get enough of cat videos!) Professionally, Nitin is a marketer at VWO, who loves to write about Conversion Optimization. Find him on Twitter: @NitinDeshdeep

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