All the top movies are appearing in 3D versions and the Consumer Electronics Show last week was full of new 3D TV’s. Why isn’t anybody buying them? We already bought our big-screen TV’s, thanks.

Suddenly 3D content is everywhere. Movie studios are using it more than ever and consumer electronics companies are even subsidizing 3D for TV programming and home video. But for all the 3D content, 3D TV sales have yet to takeoff. There are many reasons for this, but according to Conor Schutzman, who thinks a lot about such things, it mainly comes down to conflicting motivations for producers and consumers.

Content producers like 3D for two reasons: 1) they can get a 3D premium on ticket sales in theaters that effectively pays for the 3D conversion, and; 2) 3D movies are almost impossible to pirate. Notice that neither of these reasons has anything to do with your TV or mine. That’s important.

The movie industry likes to complain that they are getting killed by piracy — everything from perfect digital dubs to the more common pirate shooting the movie with a camcorder from his theater seat. Neither of these works for 3D movies, effectively killing piracy. And since 3D is made more-or-less free to the studios by our willingness to pay more to see movies in that format, doing 3D versions of most movies is a no-brainer. In fact, if enough theaters were capable of showing high-quality 3D, my guess is that we’d see all movies released in 3D (no more 2D).

That explains all the 3D content that’s appearing, but there is not much of a unified 3D home video strategy to go with it. Most of the companies have a plan for 3D but they are also in competition and want their plan to be the one to succeed. That implies a Beta-versus-VHS market confusion problem, but that’s not really what’s keeping people from buying 3D TVs. It’s more fundamental. What’s keeping them from buying is that they already bought a new TV or three during the recent digital transition. More than 100 million people in the USA alone bought a newer, generally more expensive TV over the last two years. But now that they’ve bought, new TV sales are mainly covering replacements caused by unit failures, and those only happen about every 10 years.

We have no real incentive to buy. Rooms are getting smaller, not larger, in the current economy, so the push for ever-larger screens has waned. Vendors have been trying to lure us with LED backlights and faster frame rates, but anything over 120 Hz is either: a) impossible to even notice for older eyes like mine, or; b) feels actively uncomfortable for folks raised on 24- or 30-frames-per-second. Leave it for the next generation to reach adulthood and thrive on 240 Hz TV.  They can pay for it, too.

So 3D TV’s are likely to flop, though Moore’s Law suggests that we’ll see plenty of 3D technology rolled into future sets anyway because it is already developed and because they have to use that silicon real estate for something.

But whether 3D TV’s are a success or not, 3D movies — with their completely different reasons for being — are here to stay.