Cable and set-top box companies have been trying to make interactive TV pervasive for a long time. But MegaPhone Labs says it has figured out a way to create that interactivity without a lot of expense, simply by tying an interactive service, trivia quiz, or contest to a user’s smartphone.

With DialPlay TV, the smartphone becomes the controller. Users can use phone calls, web apps, and mobile apps to take advantage of interactive programming on the TV. MegaPhone creates simple games that users can respond to by pressing a number on their smartphone, sending a reply via text message. The results can be compiled in real-time on a sports event screen or on your TV screen.

With a smartphone as an input device, DialPlay TV lets users participate in game shows in real-time. It lets them make comments during political programming at the most relevant point. If you can make a phone call, you can interact with others. And the company says it works with any TV.

The platform is cloud-based. Neither the audience member nor the TV programmer has to get any special hardware or software to interact with a TV show. Rather, they can use web apps, mobile phone apps, and simple phone calls. The audience can offer input in real-time.

Advertisers will care about this because the DialPlay TV solution can get users more engaged with typical TV programming than they otherwise might. They can also measure results for campaigns across a number of platforms. The company’s platform is being used in 43 professional sports arenas in the U.S and Canada for NFL, NHL, NBA, and MLB games. Through its apps, DialPlay TV can reach as many as 100 million households. Top customers include NBC4 and The Weather Channel.

The idea was developed by Jury Hahn and Chris Kairalla at the interactive telecommunications program at New York University. The New York-based company was founded in 2007 by Hahn and Dan Albritton in 2007. Mark Yackanich is chief executive. The company has eight employees. Rivals include Comcast, Time Warner Cable, and Canoe Ventures.

The company has raised $3 million to date from angel investors including Michael Birch, Stan Chudnovsky, James Currier, Auren Hoffman, and Chris Michel.