Facebook homepage ads have begun. They are effectively static full page takeovers with a Facebook module overlayed in the bottom right corner. In this example you see an ad unit for eBay's summer electronics event. On the right corner is a mini-Facebook ad unit (as you would see it on the right column of a logged-in page): it contains the copy / creative and like / share buttons. It's prime real estate and a huge unit... even if on the log-out screen. The interesting note however is that, when users are logged out, the social features are obviously not as effective... for instance, users cannot like, share or comment with a single action because they are not logged in. I suppose this is a necessary consequence of taking over the homepage. To solve this, you would need to prompt users much more intrusively: on their feed page.
