Midnight Friday will usher in a new era in TV history.
In accordance with federal law, all of America's 1,700 television stations will be digital by Saturday, sending out signals that will require viewers to have either a TV-top digital converter box or a subscription to cable or satellite TV.
It marks the first fundamental change in the development of the television industry, says Bill Hayes, president of the Institute of Electrical and Electronics Engineers Broadcast Technology Society.
"Color and stereo were simply refinements," he says, "whereas digital is the dawn of a whole new era of innovation for the industry."
The move creates clear winners and losers.
Local TV stations. They will be able to provide more services to audiences, because there is more room on the digital signal to broadcast multiple kinds of programming, such as concerts and local civic and sports events.
Emergency and first-responder crews. This additional space on the spectrum frees up more bandwidth for their wireless radio communications, lessening the chance that all frequencies would be jammed during an emergency.
Mobile technology. As early as this summer, mobile broadcast television could be available on phones and other handsets. Commuters will be able to watch the evening news on their cellphones and on portable players.
Advertisers. Keen to microtarget ad-skipping audiences, they are eager to exploit the kinds of interactive technologies that digital makes possible. For example, one Hellmann's Mayonnaise campaign invited viewers on DirecTV to click through an ad into a dedicated channel on which they could build a perfect sandwich and win prizes.
"We had millions of people tune in," says Jacqueline Corbelli, CEO of BrightLineiTV in New York City, which designed the campaign. "Both sides were happier, because viewers weren't being beat up by ads they didn't want to see, and the company had people who actually wanted to be on their channel."
Some 16.5 million households. That many households will go off the grid, experts estimate. Some of them have even installed converter boxes for their TV sets. But digital signals do not transmit as far as analog signals do, which means the switch will adversely impact rural users particularly.
The environment. As homeowners give up on their old TV sets, landfills nationwide are bracing for what technology expert Karl Burkart of the Mother Nature Network calls "an analog inundation" – as many as 90 million discarded TV sets full of lead and mercury toxins that will end up in dumps.
Under-35 singles, and Hispanic and African-American households. Experts say these viewers have been hardest to reach with information about how to prepare for the switch, tend to have less money to spend on upgrades, and will be slower to adapt once the curtain drops on their old TV sets.
Technical problems? Or questions related to the digital transition? The Federal Communications Commission says call 1-888-CALLFCC.