Stacy Spikes, a co-founder and former CEO of MoviePass, just launched a Kickstarter campaign to fund PreShow, an app that lets users receive free movie tickets in exchange for watching 15 to 20 minutes of advertising. But there’s a catch: PreShow is based on facial recognition; Spikes said it is to prevent users from gaming the system. While the user watches ads, her smartphone’s camera keeps track of her level of attention. The ad pauses after five seconds should the user walk away or even hide part of her face.

CNET reports that, “facial recognition is already playing an ever-growing role in your life, for good and for ill.” “We had two problems to solve: We didn’t want people creating dummy accounts, and we’re dealing with real currency at the end of the day, so we needed to uniquely lock it,” Spikes said. “Facial recognition at the phone level is just a year and a half old. You couldn’t do this company two years ago.”

PreShow also needs to make sure that the smartphone owner is the only person who can open the app (and that that person only has one account). In a demo, Spikes “unlocked the app via his iPhone 7’s front-facing camera.” The camera monitors the viewer’s attention by placing a green border around the edge of the video when the viewer is watching. But, step away or move your head, and the border will turn red, and automatically pause after five seconds.

Kickstarter donors will be the first to use PreShow when the private beta begins in July, but “the company hasn’t specified when it will be made available to the public at large” — or finalized an end user license agreement. According to PreShow, beta testing will be the process whereby the company develops its terms and conditions. But PreShow did state that the app will not record anyone as they watch or share personally identifiable data to third parties. Advertisers will receive “aggregated and anonymized data,” of information — age, geography and gender — the user provides when signing up.

Spikes co-founded MoviePass in 2011 but “was let go” after Helios and Matheson Analytics took over; Spikes said he “didn’t agree with the direction the company was going.” He began working on PreShow shortly thereafter.

“If the innovation is there in a big way — that is, universal from the consumer standpoint — it helps cinema to leap forward,” Spikes said. “And hopefully, making movie-going possibly free will radically do that again.” Unlike MoviePass, he added, PreShow will not operate in the red; “the consumer pays his or her own way by virtue of watching the ads, whether the company’s user base is 3,000 or 30 million.”

Spikes also hinted that points earned by watching ads could be used to buy products of brands integrated in the movie. In addition to the Kickstarter campaign, “PreShow has funding from an unnamed angel investor who is a former wireless industry executive with an interest in cinema.”