Instead of being able to drill down so your ad for a used camera lens will only appear to folks who've indicated on their profile or posts that they're interested in photography, options are limited to appearing for adult users in surrounding ZIP codes. Apparently as part of click-based optimization, as more people start clicking on your ad, said post will begin appearing to people with similar demographics.

Facebook said that the limited targeting is a test to help folks find local buyers, and the tool was based on Marketplace user feedback.

Business advertising on Marketplace is live right now, with Facebook saying that over the next few weeks, it'll open up Marketplace ads to all advertisers targeting users in Australia and New Zealand.

There's a scene in The Social Network where Jesse Eisenberg's Mark Zuckerberg character argues that putting ads on the site would be like shutting down the party before anyone knew what the party was about. Well, in reality, Facebook knows exactly what the party is about: selling as much advertisement as possible.