In other Facebook news: the company has partnered with Datalogix to monitor the effectiveness of its advertisements by tracking what users (or, to be specific, groups of users) purchase after seeing an ad. The good? The companies claim that $1 spent on Facebook marketing results in $3 in incremental sales. The bad? There is no way for users to opt out on Facebook – instead, they have to go to Datalogix’ site through Facebook’s help center and opt out there.