its not a great song, but a good song, so i think it did better than it should have
I expect that the label made eminem put out another pop single to generate more interest for his album but it was nothing surprising just eminem making fun of celebs as always so thats why it didn't do so great ( For eminem it's not great for other artist placing number 3 on itunes it would have been great).
Overall, don't worry about the single too much im sure the rest of his album will be better than his last