In a move that Adknowledge has long been planning — especially since it bought Super Rewards this summer — the advertising technology company announced yesterday that it is letting advertisers bid to run offers within its offer walls on applications on Facebook, MySpace, and other sites.

Super Rewards and other offer providers have built their businesses on taking lead-focused advertising from ad networks and running them inside of social networks; until recently, many offer companies also ran scammy ads from ad networks within their offer walls, although the industry has clamped down on the practice. Offers are typically some form of coupon or discount advertisement, that typically allow users to earn virtual currency for social games in exchange for making a purchase, participating in a survey, or taking another action.

Adknowledge’s move should help increase the quality of ad inventory within offers. One of the biggest problems with the offers industry has been that advertisers have not been able to clearly track their return on investment through all the layers of intermediaries.

Advertisers can now more easily bid on offers on a cost-per-action (CPA) basis along with the other ads they run on Adknowledge’s performance-driven network, and in its email marketing service. The latest version of its bidding system, called BidSystem 3.0, lets advertisers manage all of their Adknowledge buys in a single interface, seeing granular results for what sorts of ads are working, or not.

The company is also bragging that this deal makes it the fifth-largest online ad network behind Google, MSN, Yahoo and Facebook. It has been expanding its sales force in the US and around the world, and tells Virtual Goods News that it plans to try to bring in more “midrange” advertisers.

For those not familiar, Adknowledge’s business has historically been in e-mail marketing and its cost-per-click performance advertising network. It has aggressively moved in to social network advertising over the last couple of years. Besides the Super Rewards purchase, it has bought up the social ad networks of Cubix, Lookery and most recently Social Media.