He was in a movie with her, but every American Idol fan knows that Justin Guarini is no Kelly Clarkson. The more appropriate question is, why?

The guy can clearly sing. Yet he has achieved little commerical success compared to his Idol peers. Upon completion of the show, he was cut by his label, RCA, and got virtually no promotion for his self-titled debut album, Justin Guarini, released back in 2003.

That album was followed by Stranger Things Have Happened, produced and released by the label Justice Entertainment. The fact that his movie with Clarkson, From Justin to Kelly, tanked so hard also didn't do him any favors. Not that the movie -- universally panned by critics -- was his fault (Kelly even derided the picture as a contractual obligation, nothing more), but the guy can't seem to catch a break!

Justin makes occasional TV appearances and is still working on his music, but he hasn't had a lot of luck since the original American Idol season. A runner-up finish has proved good enough for the likes of Clay Aiken, Bo Bice and others -- why not Justin? Is it because he rid himself of his trademark afro? Is Kelly just too big? Why has be fallen off the face of the Earth? What do you think?

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.