With Facebook’s advertising business model still very much a work in progress the newly public social networking company is moving to bolster its e-commerce business. Facebook said in a blog post yesterday that it will begin phasing out its Facebook Credits virtual currency for in-app purchases in favor letting users pay with their own local currency. As AllThingsD’s Mike Issac explained, the whole Facebook Credits thing never really worked out as planned. Instead of simplifying the payment process across the social network, Credits ended up adding layers, as developers generally required app users to exchange their Facebook Credits for their own virtual currency unique to each app, like FarmVille cash. By switching to local currencies, Facebook is clearly hoping to increase e-commerce on the site by eliminating the extra layers. Facebook is also adding a subscription payment model, increasing the monetization options for developers, which could also increase the amount of e-commerce on the site.