Pricey 3D TVs have not been flying off the shelves since their debut early this year, local retailers say, but that doesn't mean they won't be mainstream in a few years.

Gary Paul, owner of Paul's TV Sales and Service in Groton, and Barry Levinson, owner of Roberts Audio Video in New London acknowledge that sales have been lackluster for the sets. In March, both had anticipated the arrival of more content than "Avatar" and "Alice in Wonderland," but acknowledged Friday that today's buyer may not have much to watch for some time to come.

Right now, said Levinson and James K. Willcox, senior editor at Consumer Reports and an author of its Electronics Blog, only "maybe a million" sets have sold, compared to industry projections of 4 million. The sets cost anywhere between $1,600 and $4,300, retailers say. Of course, holiday deals could help push sales.

"If you're a movie buff and you're willing to spend the money, that's there for you," said Paul. "And videogames…. But broadcast TV: we don't have that much content (for 3D). Content is going to drive the acceleration of 3D. When there are 50 channels (to watch), people are going to buy it. But the lack of content is probably the reason people aren't really jumping toward 3D."

As the year progressed, only a handful of films have become available in 3D, with only three channels on satellite to pick from. Plus, 3D glasses must be worn to watch the sets, and they cost about $150 or more apiece and are not comfortable if the viewer is already wearing glasses, Willcox said.

One development that should push 3D from a niche to a mainstream product is that TVs larger than 40 inches are now coming 3D-ready, said Levinson.

"In another couple of years, (that new large-screen TV) is going to be 3D-ready whether you want it or not," he said.

A few years ago, it might have been hard to imagine reading devices becoming as commonplace as the Kindle is now, he added.

"When the sources are easy to access and convenient, people will gravitate toward that, so it will become a mainstream product at some point because that may be all you can buy, anyway," Levinson said. "That may be a long time from now, 10 years, but the technology seems to move quickly."

This week's announcement that Toshiba will introduce a 3D set for which expensive glasses are not needed is not as promising as it might seem, added Willcox, because the sets are launching only in Japan, the screen size is small and there are "issues" with the viewing angle.

"Clearly, there's a push for 'glassless' 3D, but I don't think we're going to see it for some time," Willcox said.

Willcox and the retailers also noted that manufacturers have made deals with Hollywood studios so that only certain 3D movies can be viewed on their sets.

"It's bad for consumers," said Willcox. "Unless you bought that brand, you can't get that movie. It locks up those titles to specific manufacturers. It's reduced an already limited supply of 3D movies."

So, as the holiday season approaches, it may continue to be the "early adopters" of new technology and those needing a new TV who are buying 3D sets, Willcox said.

"You're selling pricier TVs at a tough time," he said. "This economy is horrible, consumer confidence isn't high. Given all those factors, it's done OK, but I don't think (manufacturers) are going to hit the number they projected this spring."