Google announced they’re going into all accounts that are using Conversion Optimizer or Enhanced CPC with the “optimize for clicks” ad rotation setting and changing that over to “optimize for conversions”. They’ve stated that they’ve seen an average 5% increase in conversions when changing this setting over.

https://www.youtube.com/watch?v=nRRw1M_TeYI&feature=youtu.be

If you’re not sure what exactly Conversion Optimizer is, check out this video.

This migration is going to take place in February 2012, but if you want to opt out of this, you can just fill out a form here.