First, Rihanna's album has been on the charts for over 72 weeks (billboard 200) and she hasn't left.
Second, Justin Timberlake WROTE "Rehab", so how is Rihanna tryin to be like Beyonce? Beyonce was featured on Justins Song, with NO video what so ever. Then, to top it off, Rihanna's album came out before that song with Beyonce and Justin.
Third, how is Rihanna's costumes copying Beyonce? Have you seen Rihanna's sultry, sexy, dominatrix looks? Beyonce nEVER NEVER NEVER has did that.