Here's the truly evil part:

All free-form adverts are supposed to show some kind of sponsored label, though that doesn't appear to be the case on the three posts included in this story. While Leica's shows it, neither Philadelphia post includes a tag indicating it's sponsored content. We understand that's because the Philadelphia posts are no longer boosted by ad spending, so are back to just being normal user posts.

Ad stays up in perpetuity, tag has a shelf life, after which it looks like a normal post. Can you sponsor a post for an hour like it's a seedy motel room?

Also: As these are regular posts with brief decoration, I'd assume uBO might have trouble filtering them out.