Both companies have placed virtually all their machines inside grocery stores. Dominant company Redbox has its machines split between supermarkets and McDonald's restaurants.

As a result, TNR and DVDPlay are analyzing rental habits, income levels, even personality traits of supermarket renters in an effort to determine the most profitable title selection and copy depth for grocery kiosks.

"There is a perception that our consumer base would just be mom and the kids, but we have another segment of young professionals," said Jeff Karbowiak, chief operating officer at TNR. "If it fits with [one of the key] demographics, we might take a chance on a title that didn’t do well at the box office—take more of a chance [than our competitors] might."

Through a study conducted earlier this year by Thinking Cap, TNR's biggest consumers can be split into three categories: "established professionals," "household managers" and "at-home parents." If studios are offering titles that match the tastes of any of these three group, TNR will buy more copies than what the title might normally warrant by usual theatrical measures.

Prominent TNR title buys for the established professional segment include The Groomsmen, Prozac Nation and Napoleon Dynamite. For household managers and at-home parents, TNR stocked up on Bambi II, Cinderella III: A Twist in Time and The Sandlot 2, among others.

DVDPlay, which often skews decisions toward moms, will typically order 20% more of a title than average if it is deemed particularly family appropriate.

In addition, kiosk operators have found that busy rental times can be different at supermarkets than at other home entertainment retailers.

Popular grocery holidays, such as picnic-friendly Memorial Day and President's Day, for instance, can be as lucrative for kiosk companies as the traditionally hot Christmas shopping period.

"We have seen [sales] bumps on President's Day and Memorial Day," said Tom Szwak, VP of video for DVDPlay. "We might go a little bit deeper [on copy buying] for these weekends."

Although the kiosk companies have worked their title purchasing into a fine science, studio executive sources largely view the sector as a still unproven business.

One major studio estimates that the entire kiosk sector—which includes about 4,000 locations—makes up less than 1% of its total DVD revenue.

"We are big believers in alternative delivery vehicles, and there are consumers who like to obtain entertainment in different ways, but at the same time, we have to be honest with ourselves in terms of how big this opportunity will be," said one studio executive.

An executive at a different studio lamented the fact that kiosks, like larger retailers, still primarily carry new release titles, limiting business prospects for smaller releases. But in one case, this studio was able to place a $10 million-grossing title in kiosks, and it wound up renting "phenomenally."

"We are testing the waters,"another studio executive explained. "We haven't seen a huge impact yet from them. But there is a convenience factor, and hopefully, it turns out to be a growth sector."