It's not because of Gaga. Well, not much to do with Gaga. They aired on a Wed instead of a Sun, went up against BET Awards, and also the President. It was a bad decision. And yes, of course, having a shitty show with no star power didn't help... but still... previous years sucked ass too (with Gaga there) so a craptastic show has little do with ratings if you think about it. Sit down stans.
I think its more because of it was on a wednesday and not on a saturday or friday like the years before. Its also not fair because in germany and other countries you just was able to see the Vmas today on friday and the people who watched it today you didnt count.