[bickeringyokel]

That's the possibility I'm wondering about. I wasn't really imagining they would pretend it was posted by someone you're following but surround it with some Sponsored content message that made it clear they injected it into the feed of the person you are following.

It sure seems like a terrible idea to me, I'm just trying imagine how exactly they could make it go from an interesting idea of federating, to something that is terrible as meta is one to do.

I think probably the real reason they are federating is to avoid anti-trust issues.

[not2b]

If someone on a different instance decided to follow a famous celebrity, and Meta tried to attach that celebrity's name to an ad without their permission, the celebrity would sue and it would be a slam-dunk win. Meta can't use someone's name without their permission. Even someone non-famous could sue and win. Some very big companies have gotten into trouble that way. Adding "sponsored content" is not a get-out-of-lawsuit-free card here.

There'd be nothing stopping that celebrity from shilling for a product on their Threads feed and their followers would all get any such shilling. There's already some of that on Mastodon, which is OK if instances permit it (authors, artists and small businesses promoting themselves).