"Love On Top" has always been my favorite song from '4' (also love "Party") so I'm glad to see it reach the top of the chart. They're only a few potentially crossover/ radio hits on the album. It's obvious that most of the album was NOT made with 'crossover' or mainstream in mind as a goal. So '4' is doing what it's supposed to do, having a lot of success on the R&B charts. Her last three singles (LOT, Countdown, and Party) have been at least top twenty R&B hits with LOT now going to number one and Party peaking at #2, all three songs received little promotion, just airplay. When you factor in album sales it's a highly successful R&B album, bottom line.