It will be interesting to see how this does. Seeing as they'll be touring the UK soon that may benefit them, but the far superior 'rock that body' only managed a #11 peak, and that was off the back of three chart toppers.
Well the problem I think with Imma Be and RTB's releases concurrently was that Imma Be was more popular in the US, and then performance on the Grammys made it worldwide known. So, basically, RTB's steam was taken away. But the single has already charted in many countries without release, so I'm sure it will do fine.