Conversion Rate Optimization (CRO) Statistics 2026: Results From 400 Agency Case Studies

Most conversion rate optimization statistics come from tool vendors and benchmark reports: average conversion rates by industry, how many tests win, what share of companies run them. They don't tell you what a CRO program actually did for a client.

This page does. Every number below is counted from 400 conversion rate optimization (CRO) case studies published by 112 marketing agencies, all indexed in OpenServed's directory. Each case study names a client and states the results the agency reported: conversion rate, conversions, leads, revenue, traffic and cost per acquisition.

Data as of November 2026. These are results agencies chose to publish, so they show what a successful CRO program looks like, not what an average one does. The directory keeps growing, so if you cite a number, please cite the date.

CRO statistics at a glance

• 400 CRO case studies from 112 agencies, covering 91 industries and clients in 15 countries and territories.
• 47% is the median reported increase in conversion rate. Half of the 93 case studies that state one fall between 22% and 160%.
• 51% of those case studies report a conversion rate gain under 50%. 33% report that it at least doubled.
• 76% is the median reported increase in conversions or leads (144 case studies) and 62% in revenue or sales (86 case studies).
• 40% is the median reported cut in cost per lead or acquisition, across 69 case studies.
• 78% of CRO case studies report a business outcome, the highest share of any service we've covered.
• Only 4% mention an A/B test or experiment.
• 44% of CRO case studies also list PPC, and those report larger gains.
• Small businesses are the largest client group, at 40% of case studies with a known size.
• Only 8% are Client-verified, and none record how long the work took.

What CRO case studies report

Conversions and leads are the results agencies report most. 45% of CRO case studies include a conversion or lead stat. A conversion rate stat appears in 32%, revenue or sales in 30%, website traffic in 25% and cost per lead or acquisition in 22%. Keyword rankings appear in 8% and on-site engagement, such as bounce rate or time on site, in 7%.

78% report a business outcome. That means revenue, leads, conversions or conversion rate. The share is 34% for web design and 30% for web development. CRO is sold on outcomes, and its case studies show it.

Only 7% contain no number at all. 29 of the 400 describe the work without a result, such as "Streamlined homepage navigation so key pages are one click away".

CRO results are mostly percentages. 73% of result stats are percentages, more than for PPC (68%) or SEO (62%). The 400 case studies carry 1,228 result stats, an average of 3.1 each.

Only 4% mention an A/B test or experiment. 16 of the 400 case studies refer to a test, variant or experiment in their results, such as "28% Increase in Landing Page Conversions from A/B Testing". The rest report the outcome without saying how it was proven.

CRO conversion rate statistics

The median CRO case study reports a 47% increase in conversion rate. 93 case studies state a percentage gain. A quarter report 22% or less, and a quarter report 160% or more.

Half report a conversion rate gain under 50%. The full spread:

• Under 25%: 27% of case studies
• 25% to 49%: 24%
• 50% to 99%: 16%
• 100% to 199%: 16%
• 200% or more: 17%

A 47% gain is a relative change. A conversion rate of 2% rising by 47% ends at about 2.9%, not 49%.

35 more case studies give a conversion rate without a percentage change. They state a level, such as "4.86% Conversion Rate", or a before and after, such as "Conversion rate: 3.33% to 10.90%". Those aren't counted in the median.

CRO conversion, lead and revenue statistics

The median reported increase in conversions or leads is 76%. 144 case studies state a percentage gain, with the middle half between 38% and 190%. Taken separately, the median is 64% for conversions (78 case studies) and 80% for leads (69 case studies).

The median reported increase in revenue or sales is 62%. 86 case studies state one, with the middle half between 27% and 194%. This includes orders, transactions and average order value.

The median reported increase in website traffic is 84%. 92 case studies state one, with the middle half between 36% and 236%. 78 of the 92 come from case studies that also list SEO or PPC, the services that bring the visitors.

CRO with PPC

44% of CRO case studies also list PPC. 174 of the 400 combine the two.

CRO sold with PPC reports larger gains. The median reported conversion rate gain is 59% with PPC (48 case studies) against 40% without (45). For conversions or leads it is 92% (85) against 60% (59), and for revenue 81% (27) against 46% (59).

CRO cuts the cost of a lead or sale by a median of 40%. 69 case studies state a percentage cut in cost per lead or cost per acquisition, with the middle half between 26% and 54%. 55 of the 69 also list PPC. A higher conversion rate on the same ad spend lowers the cost of each conversion.

With PPC, CRO case studies report more outcomes. 85% of CRO case studies that include PPC report revenue, leads, conversions or conversion rate, against 73% of those without.

CRO with SEO

28% of CRO case studies also list SEO. Those are the ones that report traffic: a traffic stat appears in 58% of CRO case studies with SEO, against 13% of those without.

With SEO, reported lead and revenue gains are higher. The median gain in conversions or leads is 108% with SEO (44 case studies) against 63% without (100), and the median revenue gain is 106% (21) against 52% (65). Conversion rate gains are about the same, at 50% (29) and 44% (64).

CRO for ecommerce

27% of CRO case studies are for online stores. 107 of the 400 are for retail and ecommerce clients or mention orders, purchases, checkout or a commerce platform.

Ecommerce CRO reports a median 54% increase in revenue or sales. 58 case studies state one, with the middle half between 22% and 196%. The median conversion rate gain is 50% (28 case studies), with the middle half between 31% and 156%.

Average order value gains are smaller. 18 case studies report a percentage gain in average order value, with a median of 29%. That's below our 20-data-point minimum, so treat it as a rough guide.

How CRO is sold

92% of CRO case studies bundle another service. Only 34 of the 400 list CRO alone. The average case study lists 2.5 services.

PPC is the most common partner. PPC appears alongside in 44% of CRO case studies, SEO in 28%, Web Design in 23%, Social Media Ads in 14%, Web Development in 10% and Content Marketing in 9%.

CRO sold with web design reports smaller gains. The median gain in conversions or leads is 54% when Web Design is also listed (28 case studies), against 91% when it isn't (116). For revenue it is 51% (24) against 68% (62). One likely reason: a redesign changes many things at once, while CRO on its own tunes a site that already works.

CRO statistics by industry

To make 91 industry labels comparable, we rolled them up into 13 groups (see methodology).

Retailers are the biggest buyers. Retail & Ecommerce accounts for 17% of CRO case studies (69), followed by Software & Technology (13%), Healthcare & Wellness (11%), Home, Property & Local Services (10%) and Fashion, Beauty & Jewelry (10%). SaaS is the most common single label, with 32 case studies.

Only two groups have 20 data points for any metric. Median reported gain, with the middle half in brackets:

• Retail & Ecommerce, revenue or sales: 59% (28% to 216%), 40 case studies
• Retail & Ecommerce, conversion rate: 45% (31% to 117%), 20 case studies
• Software & Technology, conversions or leads: 66% (29% to 182%), 26 case studies
• Software & Technology, conversion rate: 46% (19% to 164%), 20 case studies

Conversion rate gains are about the same in retail and software. The median is 45% for Retail & Ecommerce and 46% for Software & Technology, both close to the 47% overall.

CRO statistics by client size

Client size is the client's employee count. It is recorded for 200 of the 400 case studies (50%), so this section covers only those.

Small businesses are the largest client group, at 40%. Of the 200 with a known size, 80 involve small businesses (1 to 50 employees), 43 medium businesses (51 to 200), 27 large businesses (201 to 1,000) and 50 enterprises (more than 1,000).

Only small businesses have enough data to report. Median reported gain for small-business clients, with the middle half in brackets:

• Website traffic: 134% (73% to 362%), 24 case studies
• Conversions or leads: 67% (36% to 217%), 39 case studies
• Conversion rate: 32% (11% to 74%), 26 case studies

Small businesses report smaller conversion rate gains than the overall median. Their median is 32%, against 47% for all CRO case studies. Their lead gains come alongside a median 134% traffic gain.

CRO statistics by country

Country is the client's location, not the agency's. It is recorded for 279 of the 400 case studies (70%), so this section covers only those.

76% of CRO case studies are for US clients. 213 of the 279 located case studies are in the United States. The other 66 are spread across 14 countries and territories, led by the United Kingdom (30) and Canada (19).

US clients report a median 42% increase in conversion rate. 59 US case studies state one, with the middle half between 21% and 122%. The median gain is 71% in conversions or leads (99 case studies), 64% in traffic (54) and 56% in revenue (41).

Clients outside the US report a median 84% increase in conversions or leads. 22 case studies state one, with the middle half between 51% and 190%. No single country outside the US has 20 data points.

California accounts for 21% of US CRO case studies. 44 of the 213 are for California clients, followed by Texas (23) and New York (22). California clients report a median 62% gain in conversions or leads (27 case studies).

How long CRO takes: what the data can't tell you

None of the 400 case studies records how long the work took. CRO is usually described as a program of tests over months, but this dataset can't measure that.

Only 15% mention any time period at all. 61 case studies include a time reference somewhere in their result stats, such as "year over year" or "in one month". The other 85% give a result with no window.

If you're comparing agencies, ask over what period each number was measured, and against what. A conversion rate lift over two weeks of testing and the same lift year over year are different results.

The agencies behind the data

Three agencies publish 23% of the CRO case studies. KlientBoost has 48, scandiweb 22 and NoGood 20. Half the agencies have two or fewer.

One agency supplies more than a quarter of the lead and conversion rate data. KlientBoost supplies 41 of the 144 data points for conversions or leads and 28 of the 93 for conversion rate. Without it, the median gain in conversions or leads is 89% instead of 76%, and in conversion rate 50% instead of 47%.

How much of this data is verified?

Only 8% of CRO case studies are Client-verified. 30 of the 400, from 23 agencies, carry OpenServed's Client-verified badge, meaning the named client confirmed the results. The other 92% are agency-reported.

There are too few verified results to compare. No metric has 20 verified data points, so we can't say whether verified gains are higher or lower.

Keep this in mind with every number on this page. A published case study is an agency's best work, described in the agency's words. Without a client confirming it, it's a claim, not a benchmark.

What this means if you're hiring a CRO agency

• Treat a 47% conversion rate gain as the typical published win, not a promise. Half of the case studies that report one stay under 50%, and these are the programs that went well.
• Ask for the conversion rate before and after. A relative gain means little without the starting rate.
• Ask how the result was proven. Only 4% of CRO case studies mention an A/B test or experiment.
• Ask what happened to revenue or cost per lead, not only conversion rate. CRO case studies report a median 62% revenue gain and a 40% cut in cost per lead or acquisition.
• If you run paid ads, look for CRO paired with PPC. Those case studies report larger gains in conversion rate, leads and revenue.
• Ask for the timeframe. None of the 400 case studies records how long the work took.
• Ask whether the client confirmed it. Only 8% of CRO case studies are Client-verified.

You can browse every case study behind these numbers in OpenServed's CRO agency directory, and filter by industry, client size and location.

Methodology

• Source: all 400 case studies in OpenServed's directory that list CRO as a service, as of November 3, 2026, from 112 agencies. Each links to the agency's own published case study.
• Result stats: each case study carries the result stats the agency published, as free text. We assigned each stat to a metric by keyword matching: conversion rate, conversions, leads, revenue, traffic, keyword rankings, cost per lead or acquisition, on-site engagement and page speed.
• Percentages only: medians use stats that state a percentage change. Plain counts, dollar figures, multipliers such as "3x conversion rate" and before-and-after pairs are left out, though they still count toward what case studies report.
• Ad metrics kept apart: stats that name paid media, ads, cost per acquisition, ROAS or email are not counted in the conversion, lead, revenue or traffic medians. That removes 19% of all stats. Cost per lead or acquisition is reported separately, as a percentage cut, and cuts of 100% or more are left out.
• One data point per case study: if a case study has several stats for the same metric, we use the first one listed. Conversions and leads are combined, using whichever comes first.
• Median and middle half: we report the median, not the average, because a handful of very large gains would distort an average. The middle half is the range from the 25th to the 75th percentile.
• Minimum sample: we report a segment only when it has at least 20 data points for that metric.
• Ecommerce: case studies for retail and ecommerce clients, or whose results mention orders, purchases, transactions, checkout or a commerce platform.
• A/B tests: a case study counts as mentioning a test when its results refer to an A/B test, split test, test, variant or experiment.
• Missing details: client size is recorded for 50% of these case studies and location for 70%, so those sections cover only the case studies that have them.
• Bundled services: 92% of these case studies list other services alongside CRO, most often PPC and SEO. Results can't be attributed to CRO alone.
• Industry groups: we merged 91 industry labels into 13 groups for the roll-up figures. Client size uses employee count: small is 1 to 50, medium 51 to 200, large 201 to 1,000 and enterprise more than 1,000.
• Selection bias: agencies publish their wins, and the directory is not a random sample of the industry. Three agencies account for 23% of these case studies.
• Agency-reported: except for the 30 Client-verified case studies, results are as published by each agency and haven't been independently confirmed.

Cite this data: OpenServed, "Conversion Rate Optimization (CRO) Statistics 2026: Results From 400 Agency Case Studies", November 2026, https://openserved.com/blog/cro-statistics