The song only took off when Christina was added onto it, the solo version flopped to hell for 2 months before Christina saved it. It's not a stretch to say that she has a lot to do with the success of the song and deserves a lead artist billing. And it's not like she can't get anywhere on her own, Your Body went gold with almost no promo whatsoever and We Remain is in the top 100 as we speak once again with no promo from Christina herself