How Optimizely Improved Facebook Ad Retargeting Cost by 83%

While I'm sure the methods in here are valuable, the initial claim of 83% seems suspect.

> After launching the Adaptive Audience campaign, CPA for our technical audience went from $34.47 for general remarketing to $18.80 for the targeted remarketing via adaptive audiences, so an 83% overall improvement for CPA for our technical audience – which is a huge win!

This seems like a misleading way to phrase this. When I hear 83% improvement from $34.47, I expect a 83% ($28.61) drop, ie, 34.47 * (1 - 0.83) = 5.86.

This is more reasonably a (34.47 - 18.80) / 34.47 = 45% drop. Still impressive, but not the same.

Is it really standard to express your improvement in these terms? This would make it trivial to have a >100% drop in cost, which is clearly wrong.

It's always great to reduce costs where you can.

It's not always great, in my humble opinion, if this results in my being inundated with more ads on the internet. I wish this technology would go away.

I've been working pretty closely with Optimizely for the last year or so. I would go ahead and say its difficult/impossible to realize the advertised effect of their product. Can't speak to this one directly though.