We watched it with our 7yo daughter, who has played the game once or twice when I showed it to her, but is nowhere near an addict. She's been waiting for this moving for months, purely based on the trailers and implied entertainment value, and not at all because of the game itself.
I suspect the 9 month marketing onslaught was to ensure that the movie would be watched by people who haven't played the game, and it clearly worked, having opened at #1. While Angry Birds has been a very popular game across all mobile platforms for a few years now, there's no way they could rely purely on their gamers to support the movie and allow it to be a huge success.
In fact, after watching the movie, I introduced the game to my daughter again, and she still hasn't really taken to it. While I'm sure they got a huge number of new installs after people watched the movie, I'd be surprised if their long-term player base increases in line with the movies success. Just because the movie is based on a game doesn't mean it's aimed only at the gamers.