Rihanna's music fits in perfect in the Itunes/ringtones era, it's singles after singles being marketed. Very few artist can keep an artist attention beyond singles (Jay-z, Kanye, Beyonce, Alicia Keys, Dr. Dre, Eminem).

I wouldn't brag about Rihanna's ability to sell singles, Flo Ridah and Pitbull sell singles and i don't think neither of those dudes are respected or looked at beyonce some pop rappers.