Google has opened up Conversion Optimizer to more advertisers. The AdWords tool is now available to those who've had at least 15 conversions in the past 30 days.
If you're not familiar with Conversion Optimizer, Search Engine Watch expert David Szetela did a nice write-up of the tool last January. Basically, it's a bid automation tool that uses conversion data to place ads in AdWords auctions.
Google says that their data is showing the average advertiser increasing conversions by 21% when they use Conversion Optimizer. Also, their CPA (cost-per-acquisition) costs dropped by 14%.