Usually not. Button-colour tests win 16% of the time. 81% change nothing measurable.
Cheap to run, and rarely the thing that moves a page.
Small sample. Few of these tests cleared the bar. The 95% interval on that win rate runs 7% to 32%, so read it as directional rather than settled.
| Tests analysed | 32 tests |
| Beat control | 16% |
| No measurable difference | 81% |
| Lost to control | 3% |
| Median lift when it won | too few winners to report |
All 5 winners fell between +5.2% and +68%. Median traffic per variant was 2079 visitors. Most ran on homepages (11), carts (9), category pages (6).
Only the button's fill, border or contrast changes. The label is identical, the size is identical, the position is identical.
Adjacent categories, and how often they win: CTA copy (12%), styling (15%), layout (19%).
These are individual tests, not rules. Each ran on one site, with one audience, against one page we are not showing you. They are picked to be illustrative rather than sampled at random, and a change that won here can lose on your page for reasons none of this captures. Read them as prompts for what to test, not as findings to copy.
Button colour is the most-repeated tip in conversion optimisation, and it survives because the few wins are memorable while the flat results are not. A flat test gets abandoned rather than written up.
| change type | win rate | tests |
|---|---|---|
| Layout | 19% | 351 |
| Hero image | 17% | 160 |
| Form | 16% | 81 |
| CTA colour (this page) | 16% | 32 |
| Styling | 15% | 1414 |
| Price framing | 13% | 117 |
| CTA copy | 12% | 315 |
| Body copy | 11% | 337 |
| Split URL | 11% | 1164 |
| Headline | 10% | 918 |
| Social proof | 9% | 196 |
Our data does not support a universal answer. The winning tests moved in different directions on different pages.
Only if it is cheap and you have traffic to spare. A layout test at 19% is better odds on the same effort.
This is every Mida account that ran a readable test — in-house marketers, founders, product teams, and agencies working on client sites. Nothing here is filtered by who ran the experiment or how experienced they are.
Low win rates are normal in experimentation, including at the top end. Microsoft's experimentation team, reporting on its own platform, found that only about one third of ideas improve the metric they were designed to improve — and that roughly another third actively hurt it. That is a dedicated experimentation organisation with research, prioritisation and review behind every test.
A mixed population like this one runs below that. The gap is roughly what disciplined practice buys you: ideas grounded in research rather than opinion, one variable at a time, and tests built so the result can actually be read.
So treat these as a general base rate, not a target. If you would rather not close that gap the slow way, find a CRO agency in the United States, the United Kingdom, the Netherlands or Australia — or browse every region.
A win is a variant that beat its control on that test's primary goal with a statistically significant result. Tests that never got enough traffic to say anything either way are excluded. The methodology has the full detail, including what these numbers cannot tell you.
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