What does "Conversion Rate Optimization" mean?

Definition of Conversion Rate Optimization in the context of A/B testing (online controlled experiments).

What is Conversion Rate Optimization?

Alias: CRO

Conversion rate optimization (a.k.a. CRO or simply conversion optimization) is the practice of improving a website, mobile application or other software such that it converts a greater proportion of potential clients to clients. For example, in e-commerce it would amount to altering the on-site and off-site user experience such that a larger proportion of people purchase and/or they purchase items that result in higher revenue for the merchant.

Examples of on-site changes include altering the visual appearance, user flow, processes, messaging (copy), as well as improving the underlying technology such as improving the speed of the site or the quality of a recommendation algorithm. Examples of off-site changes include altering e-mail onboarding campaigns, making sure the messaging used in PPC campaigns is consistent with the website copy, and others.

Way too often, especially in mature and complex websites improvement of the conversion rate can be achieved by removing content and visual distractions (uncluttering) instead of adding new elements or simply changing existing elements.

Contrary to the presence of conversion rate in the term conversion rate optimization, a CRO specialist does not focus on conversion rates, though they are often important Key Performance Indicators. In fact, an important part of the work of a CRO expert is establishing which metrics reflect key business objectives the best while also being actionable.

Conversion rate optimization often involves conducting A/B tests and Multivariate Tests in order to manage risk and to estimate (see estimator) with some precision the effect of certain interventions aimed at improving the achievement of business goals.

Like this glossary entry? For an in-depth and comprehensive reading on A/B testing stats, check out the book "Statistical Methods in Online A/B Testing" by the author of this glossary, Georgi Georgiev.

Related A/B Testing terms

A/B TestConversion RateA/B Testing

About the author

Georgi Z. Georgiev

Georgi has over twenty years of experience in online marketing, web analytics, statistics, and design of business experiments.

Author of the book "Statistical Methods in Online A/B Testing", white papers on statistical analysis of A/B tests, and a speaker, he has been distinguished as a winner in the Data & Analytics category of the 2024 Experimentation Thought Leadership Awards.

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