It's pretty easy for absolutely terrible decisions to be made at a smaller startup, especially when you don't have the tools handy to prove that they're terrible decisions.

I happen to work at a smallish eCommerce startup with lower traffic volumes and a 5% (checkout–not engagement) conversion rate, and while A/B testing small (or even large) changes to our homepage haven't proven fruitful, two small changes to our product pages have made a meaningful difference to our bottom line. (And I mean small as in I spent maybe an hour total setting up those tests while on an Optimizely free plan.)

So yeah, I'm an Optimizely and A/B test fan.