Imitation is the sincerest form of television – and reality programming is no different.

The genre of reality shows, which started with Twentieth Television’s “Cops,” is showing no signs of slowing down this year, and the subject matter is expanding from street cops to space aliens.

This year, at least a dozen new reality shows will be pushed at NATPE and for the most part, they are similar to other shows already on the air.

Yet even with that many new shows, reps and syndicators – though concerned about an overcrowded marketplace – are not having panic attacks. And the seemingly endless variations on a theme don’t upset syndicators. After all, if there are close to two dozen talk shows on the air and in the works, then why can’t the same strategy work in reality programming?

Among the new shows are series about the Coast Guard, border patrols, con artists, emergency room teams and more cops. There are also several series, influenced by the success of Fox’s “X-Files,” that are focusing in on paranormal activities.

While the market is crowded, as long as the shows keep working, it may be awhile until it thins out.

“The shows are on because people still watch,” says Bill Carroll, vice president, director of programming, Katz Television. “Reality shows have become the cinema verite look at life. The fact is that success breeds variations on a theme.”

Chuck Larson, president, MTM Distribution, which syndicates “Rescue 911,” agrees. “To the viewers, real life is stranger than fiction.”

“There is nothing as gripping as watching a rescue – each story has heroes,” says Larson.

But Larson concedes that it is getting crowded out there. “The shows that are currently on will be on for a while, but the new ones will find market support tough to come by. It will start to slide in a couple of years.”

In the immediate future though, Larson anticipates that it is talk shows that will take the hit and reality will get the boost.

For Phil Oldham, executive vice president of Genesis Entertainment, whose product includes firstrun series “Real Stories of the Highway Patrol,” says the success of the genre is due to many factors.

“Reality shows cut across a lot of demographics,” says Oldham, whose company also distribs “Juvenile Justice,” “Emergency Call” and “Top Cops” in off-network syndication.

“They get a lot of male viewers that are frequently light TV watchers while still getting a lot of women.” Another advantage is the low production cost. “You can’t produce a sitcom for strip.”

On a creative level, Oldham says “the quality of what you can do today production-wise tends to create reality shows that are more compelling than fiction.”

Twentieth Television head Greg Meidel, whose “Cops” and “America’s Most Wanted” are two of the genre’s most successful shows, is confident that the marketplace will continue to support these shows.

“Everyone is waiting for ‘Cops’ to run out of gas, but we have arrested the competition,” says Meidel. “There are going to be copycats. Fortunately, the pie can be cut a little thinner right now, but at some point, we do cannibalize.”

Another plus for the genre, now that it is established, Meidel says, is a lack of advertiser resistance to reality shows.

“We have done the job of educating the buyer about the show and have made them as advertiser-friendly as we can,” Meidel says.

“We walk a fine line of jeopardizing our ratings and our ad revenue if we push too far. In the last few years, advertiser resistance has gone away.”

But the growth of talk shows, the birth of two new networks, a continued reliance on infomercials to fill time periods and a crackdown on clearances by CBS, NBC and ABC may make it harder for these shows to find homes.

“There is only so much room in the highly visible time periods,” says Katz’s Carroll. “Prime access (the hour before primetime) is the most difficult time period to sustain success in. Some shows are able to sustain success in the afternoon, a less forgiving time period than late fringe.”

“Day & Date,” an hourlong news magazine show from CBS and Group W that is going after the 3 p.m. to 4 p.m. timeslot is hailed by some as a great victory for reality and magazine shows.

“As a lead-in to local news, that is a landmark approach to a time period,” says Scripps Howard Productions president David Percelay, who anticipates a similar opportunity for a reality programmer should one of the networks choose to get out of the morning news business.

The drawback to such a time period is that stations, which are already not known for their patience in letting new shows find audiences, view the news lead-in as one of the most important slots.

“Patience levels won’t allow the shows to founder,” Percelay says.

Follow @Variety on Twitter for breaking news, reviews and more