The only time Rihanna has ever had a break in her career was for most of 2009 where she didn't really do anything, except sing the chorus to Run This Town (and get beaten up).
Rihanna is in a difficult situation though. They were going to wait another month or more to release this single, but they had to bring forward the release date due to high demand (fake versions of the song started charting). So it's more the public's fault really.
But I agree, Rihanna should've waited longer before even putting this song on the Internet and radio. Her single before that was pretty darn awesome imo (better than We Found Love), and it's now gotten completely overshadowed by this new song, which is a shame.
Lady Gaga isn't as bad as it seems either. I really don't like her, but there was that time where she was releasing a single every week. A LOT of artists have been doing that for years and years, before anybody even knew of Lady Gaga, it's just that Lady Gaga is the biggest pop star on the planet, so all her promo singles shot straight into the top 10.
Katy Perry, Black Eyed Peas, Eminem, David Guetta, Drake, Beyonce, Taylor Swift and many others have done the same, but they're not as popular as Lady Gaga. Their promo singles all did badly in the chart and went unnoticed.