Rihanna Sales Jump

It seems that Chris Brown's sales have slipped off, which is expected and understandable. It also seems like Rihanna's sales have leaped, which is expected. But not really understandable. What is the mindset of people who rush to buy her album because she was beaten? She was already a known quantity, and Good Girl Gone Bad has been out for 2 years. And most of the people who are sympathizing with her are people who were already her fans (i.e., people that already owned her albums). So what gives?