It's not so much rap nowadays as it is pop, hip-hop and R&B. Those three genres get marketed FAR too much (and that's an understatement). They don't have hardly any distinguishable qualities from each other, there are so many pop songs that sound the same even from different artists. Even some of the titles are too similar. Take Carrie Underwood and Chris Daughtry, two people that were at the top in AI in the same season. Both of their debut songs were "I'm so over it" by CU and "It's not over" by CD. Both songs sucked yet sold very well because they were marketed.
Pathetic.
This will only take a moment of your time. *steals your watch*