Google is championing the OpenSocial Advertising Network, an alliance between itself, MySpace, LinkedIn, Orkut, Ning, Plaxo, Friendster, Saleforce, Oracle and other social spaces. Open Social is a series of APIs that will allow developers to create apps for social networks and include Google driven advertising.

The move comes days before Facebook is expected to announce an advertising network API of its own that will allow marketers to tailor ad-delivery based on characteristics of Facebook users. Earlier today, CNet News reported Facebook board member Jim Breyer suggested to Silicon Alley that Facebook might also work with OpenSocial.

Social network applications like Facebook are starting to become more like portals than communities with an increasing number of users setting the networks as their web-session starting points. As user habits take them deeper into social networking applications, advertising is expected to both fund expansion and provide profits. Social networks are especially attractive to marketers as the amount of information shared by individual members makes narrow-casting ads far easier.