The Phase 1 movies didn't cost that much to make (except maybe Avengers), so a return of that much is very much a profit.
Okay, but "Thor" cost more than the first Iron Man movie. And "Captain America: The First Avenger" cost slightly more than the 2008 movie, as well. And both films earned a smaller profit than the latter. I don't think 2011 was a great year, profit wise, for the MCU; which is ironic for me, considering that I prefer both movies over "Iron Man".