It's still a trickle, but at least the number is growing. MediaPost reports that the mobile video audience in the U.S. has grown by more than one-third this year to eight million, according to a new study by mobile market research firm MMetrics.

"If operators and handset manufacturers or publishers are hoping to see a mobile video take off, this is good news," said Mark Donovan, senior analyst at MMetrics, in the article, even if the audience "is still small compared to the Internet and TV."

Once the carriers begin to price mobile TV properly, or more ad-supported, free channels appear, the audience could grow a lot more than this. Right now, it's pretty complicated for the average person to sort through the various streamed and broadcast TV options available, most of which only work with certain specific handsets and add significantly to monthly plan costs.

Mobile Video Audience Grew To 8 Million: MMetrics [MediaPost]