Pretty much, although popular teams, not good teams. St. Louis right now is a unique situation because they have a bitch fight with the city of St. Louis. Well-established teams with popular fan bases will be unhappy having to sacrifice season ticket sales just to promote a game in London. But teams that might need corporate sponsors to fill the seats to prevent the game from being blacked out are happy to do their part to promote international interest in the NFL.
That being said, I would actually like it if the NFL were popular in London and, let's face it, St. Louis doesn't really cut it.