Google has lowered the requirements for using Adwords Conversion Optimizer, a CPA-based bidding feature, again. Now any campaign that has generated at least 15 conversions (rather than 50 conversions) in the past 30 days is eligible to run on Adwords Conversion Optimizer.
Google recently made it possible to import your Google Analytics goals to your Adwords account. This allows you to select optimizing based on the conversion data from either Adwords Conversion Tracking or Google Analytics goals, when running your campaigns on Adwords Conversion Optimizer.

