Tune in to an episode of HGTV's House Hunters on any given evening, and you'll see a team of home buyers and their real estate agent in action.

Behind the scenes, buyers and agents learn the skinny about what's real and unreal on reality television.

The show seldom deviates from this formula: The buyers discuss their tastes, then are shown three properties. Viewers hear their critiques and get a sense of property values in given locales, then learn which house has captured the buyers' fancy.

So discovering what really happened during several episodes taped in Chicago recently is a bit like pulling back the curtain to reveal the real Wizard of Oz.

A few months ago, as they were looking for another set of buyers, the producers stumbled across the blog of Chicago Realtor Eric Rojas (score another one for social marketing). They asked whether he had a willing buyer.

He did. But Kurt and Kelly Schnakenberg had to be more than willing to appear on television. They also had to have the financial wherewithal to actually close on a house, and they had to have the right personalities for the show, which they demonstrated in a videotape sent to the producers.

Rojas, meanwhile, had to fill out a questionnaire about how he does business.

For the show, the couple looked at three properties in the city's Lakeview neighborhood: a $415,000 loft, a $355,000 vintage condo with a kitchen that needed work, and a $400,000 loft-style townhouse that needed updating.

They bought one of the three, but one of the other two was already under contract to someone else, and they saw the third after they had pretty much made up their minds.

The conversations weren't exactly the same as the show portrayed them, either. Kurt Schnakenberg said he and his wife debated the merits of various condos, but that it was never so serious as the show suggested and was "usually over a bottle of wine."

Chicago agent Carrie Georgitsis, who showed properties to her father for another episode, had no idea how tiring it would be until she found herself involved in 40 hours of taping for what amounted to less than 25 minutes of programming.

She had to say the same things over and over while the camera crew shot her conversations with her father from various angles, and she had to be careful not to tip off viewers which property he chose.

Some of the lack of authenticity is due to the fact that House Hunters is expected to be entertaining, as are other reality shows.

But there are real-world considerations.

For example, if it turned out that the buyers had bad credit and couldn't close, there would be no happy ending and no "after" shot showing them in their new quarters.

In addition, sellers and homeowners associations, where applicable, have to agree to the taping, and some don't want to be bothered or don't want to deal with the legal ramifications if a crew member gets hurt.

And if the buyers and agent are unlikable or mumble, do people want to watch them buy a house?

Rojas doesn't think so.

"House Hunters is house candy," he said. "It's not realistic; it's directed. You don't learn anything about buying. You learn about real estate values. You learn about how houses look."

Despite all that, agents who've appeared on it say they still watch the show and would go back on it. They say it's great marketing exposure, particularly because programs are repeated.

"It's totally fake, but does anybody think reality TV is real? It's all canned, but it's fun to watch," said real estate agent Karl Vogel, who was featured in an episode helping a Boston native find a house in Chicago. "Who can say they don't like to be on television, except you look fat?"

The Schnakenbergs, who had never seen the show before they were on it, plan to capitalize on their 30 minutes of fame when it comes time to sell their condo.

"Listing it 'as seen on HGTV' couldn't hurt us," Kurt Schnakenberg said. "I'm not sure if it will get us more money, but it will help us get more showings."