He needs to go with a more alternative sound or a trendy sound. At least for the lead single to trick the GP and then go with the "Glam sound" with the rest of his album. You have to actually gain a fanbase in order to cater to a fanbase.
Firstly, his image is too far too flamboyant and outlandish. Just look at his debut album's cover. Considering the fact that 50% of Americans openly or secretly hate gays, the odds aren't too good. Then add on his super feminine image which put even more of the general public off of him. People who may have been interested in him would never support him because of the AMA's and because his first CD cover was just too gay for people to be seen with. Secondly, his music just's alright. Not bad, but nothing extraordinary. It just seems too boring, compared to his over the top personality. People want something more than P!nk rejects to listen to.
I think he doesn't have a large enough fanbase because his image/personality is so extreme? I mean, not very many straight men are going to want to admit to listening to him if they do. And some teen girls are probably more wrapped up in either flashy pop GIRLS or straight boys like Justin Bieber. There just isn't as big a fanbase for gay males I guess? Which is unfortunate. And yeah, there have been successful gay males before but they all didn't reveal their orientation until after they became successful and had a fanbase (Elton John, George Michael...)