The EP was just an excuse to put her on X Factor, get her back in the public eye and probably fulfill a prebooked RVP appearance. There has been no ongoing promotion beyond the X Factor and RVP performances so a massive drop was inevitable.
Collide, however, was a failure. It was meant to be her return to the scene and kick off the third album campaign. But the song was rubbish and I think was her first to seriously struggle for airplay - basically because the likes of Radio 2 didn't like it.