[blumkvist]

This. I haven't seen meaningful lifts from changing button colors, wording or all these things I read on guru blogs. Most (all) of the tests I've seen reported on blogs fail miserably at the statistical test, not to mention no DoE, no blocking, no theory and a thousands other things that made the test invalid.

The only way I can see that a change in colors or wording would provide a lift is if the original was confusing, which shouldn't be the case.

[vfrogger]

While I generally agree with you. I have seen adwords tests where extremely minute changes in wording caused statistically significant increases in conversion. The biggest had to do with a campaign with the word "seeds". For whatever reason, changing the plural seeds to a singular seed doubled conversion.