A few months ago, neo-jammer John Mayer was performing in front of a crowd of a few hundred fans, mostly high school girls, at “Jammin’ on Main” in Cincinnati. He wasn’t even the headliner. On Friday, he played to an adoring sold-out audience at the PromoWest Pavilion.

Mayer has risen to unbelievable fame in a relatively short amount of time with only a small number of singles – and it shows. Mayer’s overblown ego was the centerpiece of an otherwise un-noteworthy show.

The show opener was Martin Sexton, a veritable one-man band, who not only sang, but provided his own guitar and bass. Sexton’s gorgeous voice flowed through the pavilion, bottoming out in a low baritone before soaring back into a believable falsetto.

Crowd-pleasing Guster took the stage after Sexton, delivering an enjoyable set filled with the band’s rootsy rock. The set started out strong, with a pounding, passionate rendition of “Happier” – arguably the group’s best live song.

Guster’s performance was the perfect blend of fast-paced songs and ballads, which mostly served to highlight the amazing talents of percussionist Brian Rosenworcel. It was worth the price of admission just to watch Rosenworcel, who relies solely on hand drums, and his crazy antics – this guy really gets into the show.

It doesn’t hurt that Guster has a stockpile of highly enjoyable, sing-along songs. Highlights included the moving “I Spy,” “Barrel of a Gun” and the finale “Fa Fa.”

But, of course, the 3,000 or so people jammed into PromoWest weren’t there to see Guster – they were just waiting for John Mayer. And John Mayer they got, for better or worse.

Mayer’s biggest problem is he’s not yet comfortable with his stage presence. Mayer’s plaintive, guitar-strumming songs are better suited to a smaller venue, where taking time out to tune a guitar and occasionally mumbling lyrics are more acceptable.

Sold-out arena acts, which Mayer will soon become, are expected to be a little more polished and to have a more commanding stage presence. He strived to achieve something in between, sharing a few pointless anecdotes and flirting with women in the crowd, but he didn’t fit with the venue.

Mayer’s biggest draw right now is his face, which, as adorable and boyish as it is, isn’t enough to make up for his unmemorable music.

Mayer has talent; that is undeniable. The mere fact that he stands up on stage, singing his own songs and playing his own guitar separates him from the legions of performers relying on snazzy dance moves, lights and smoke.

He tooled around on stage, chatting amicably with the fans, ably singing his popular “83,” “Your Body Is a Wonderland” and “No Such Thing,” and even decently covered part of The Police’s “King of Pain.”

It’s easy to understand why Mayer is popular among the college crowd. His songs are easy to listen to, his most controversial lyrics are an ode to the female form, and his personality is as goofy as the boy next door. But … he and his ego just don’t deserve sold-out pavilion shows.

Mayer is enjoying every minute of his bout with fame. And really, who can blame him? About 3,000 attractive young people hanging on to your every word might boost your ego a bit too much.