It happens a lot in most modern r&b and mainstream rap acts, a lot of artists will base their entire song on a sample and simply perform over it. I can't stand it when it's that uninspired. Kanye West comes to mind instantly, i'm pretty sure he only sampled Curtis Mayfield's 'Move On Up' so that people would recognise that tune and it'll sell due to that.
With me i often end up being turned on to the artists that an act have sampled. An example is Public Enemy's 'She Watch Channel Zero?', i heard that and thought the riff was awesome so went out and got Slayer's Reign In Blood.