Amazon, watch out. Earlier today, Google launched an affiliate ad network. Or, rather, it rebranded Performics, the affiliate ad network that came along with its purchase of DoubleClick, as the “Google Affiliate Network.” As with other affiliate networks such as Amazon’s, participating Website publishers get paid a fee for each referral that results in a sale. Existing advertisers include Bank of America, Barnes & Noble, Citi, Target, and Verizon.

The service isn’t yet integrated into Google AdSense (publishers and advertisers still have to set up separate accounts), but that would be a logical next step. An integration with AdSense could add a contextual element to the affiliate ads placed through the network. The more relevant Google can make those affiliate links, the more that consumers will actually click through and buy (in theory).

Google also continues to experiment with a pay-per-action advertising program, which is still in beta. At some point, it might make sense to consolidate that effort into the Google Affiliate Network as well.

Update: Google will actually be phasing out the PPA program at the end of August as part of the integration with DoubleClick. You can read more details at the blog post here.