With TV networks and studios putting more of their programming online --through their own sites or portals such as News Corp. and NBC's Hulu--Web viewers will increasingly shift from video "snacking" to full-length TV episodes and movies in the next five years, according to a new study on online video by eMarketer.

But a more seamless melding of the two media is still years away, as most people still prefer to watch TV shows on TV. That's in no small part because of lingering technical hurdles to watching high-quality video online and connecting a computer to a TV.

Even so, it's become clear that online video has gone mainstream. eMarketer estimates that one in two Americans, or 154 million people, will watch a video at least once a month in 2008. By 2012, the audience will hit 190 million as growth gradually slows over the next several years.

Recent studies also highlight the consumer shift away from TV to the Internet and the PC. Nearly 70% of those surveyed in the "State of the Media Democracy" study last month by Deloitte & Touche's Development unit said they considered their computer to be more of an entertainment device than the TV.

Furthermore, an IDC study released last week found that those with a home Internet connection spent more time surfing the Web (32.7 hours per week) than watching TV.

The recently ended Writers Guild of America strike may also hasten the migration to Web video. eMarketer cites a pair of separate studies by Interpret LLC and Burst Media in which, respectively, 35% of adult consumers said they had changed TV viewing habits because of the strike, and 26% said they would probably watch more online video.

More than 10 billion videos were viewed online in December, the most ever for a single month, according to comScore. The changes aren't lost on advertisers. A study last week by Forrester Research and the Association of National Advertisers found that 62% of marketers believed TV advertising had become less effective over the last two years. It also revealed that 87% of marketers plan to spend more on Web advertising this year.

The influx of ad-friendly professional content online means not only more TV episodes pushed out to the Internet, but more original programming tailored to the Web. The eMarketer report points to "Quarterlife," the MySpaceTV show produced by "thirtysomething" creators Marshall Herskovitz and Edward Zwick, that gained a following online and is now being repackaged as an hour-long TV show by NBC.

"So, Internet-TV convergence will increasingly become a full-circle phenomenon," according to David Hallerman, who authored the eMarketer video study.

For all of the growth in Web video, the firm cautions, the sector will be held back by technological and other factors. It noted that Wired's February cover story on "Why Things Suck" included online video because high-quality, easy-to-watch video streaming is still nowhere in sight.

If streaming quality is still sporadic online, watching Web video via the living room TV is an even more distant goal. While 71% of consumers surveyed by Deloitte would like to be able to easily connect their TV to the Internet, even Apple hasn't yet made a breakthrough on that front with its AppleTV device.

An improved ability to search Web video--with relevant video links and previews across all sites--will also be required to help viewers navigate the growing amount of professional programming available online, according to eMarketer.

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