We started using Optimizely and we're blown by the results so we started creating aggressive campaigns. But then we realized something was wrong and I would appreciate any help we can get.
We tested (for example) on the homepage instead of a blue CTA, we created a variation with a green CTA and we saw a 35% increase in conversions with the variation. So then we switched things and set the green CTA as the control and the blue CTA as the variation. If it was really true that the green CTA is better we should now be seeing a 35% decrease in conversions with the variation of the blue CTA. Instead, the variation came back with a higher conversion rate.
I can't pinpoint what we're doing wrong, but in general all the variations come in with a higher success rate than the control, but if we switch things around and set the variation as the control, the results don't switch.