This startup built a business by watching where we tweet

When Pepsi needs to keep tabs on the competition — I think you know who I’m referring to — the company uses a new secret weapon: A social media analytics startup called Hyp3r that cares much more about where people are tweeting than what they’re tweeting.

Hyp3r uses geo-fencing technology to rope off points of interest in the real world, then collect virtually all of the public social media posts shared within those boundaries from sites like Twitter, Instagram and Facebook.

It sells its services to big-name marketers, like Pepsi, so they can monitor and engage with customers posting from events like concerts, ball games or theme parks. Engaging could mean something as simple as liking or commenting on a post or something as advanced as sending free drinks to a customer celebrating a birthday.

Or, in Pepsi’s case, it could also mean checking in on your rivals. Mike Foley, who runs food service marketing at Pepsi, says his company uses Hyp3r for a number of different events, but has also geo-fenced the offices of some competitors to see what public posts are coming out of enemy territory.

”It’s totally legal,” Foley said with a laugh after explaining how Pepsi keeps an eye on the competition. “I’ve been doing this for over a decade, and I haven’t seen anyone do what [Hyp3r] has been able to do with location-based [data].”

The fact that marketers collect and analyze our public social posts is not new. It’s been happening for years. But Hyp3r’s customers, brands like Disney and Marriott, say the startup is confronting an issue other social media management tools don’t: Visibility. Brands usually monitor posts for predetermined keywords or hashtags. But most people don’t mention “Marriott” when they post a pic from the pool.

That doesn’t matter with Hyp3r. So long as users include a location on their post — any location tag will do — Hyp3r can collect it. And brands can act on it.

Marriott liked the idea so much that it recently inked a deal with Hyp3r to use the technology for all of its 4,500 hotels worldwide. The hotel giant has been using Hyp3r to do things like pass out free drinks and room upgrades to guests who celebrate a birthday or anniversary at one of their properties.

“To be able to deliver guests a couple of cocktails when they were posting on their social channels ... The technology gets you halfway there, but it’s still very important to have that human component,” said Matthew Glick, senior director of global creative and content marketing at Marriott.

Disney, which has a small investment in Hyp3r because the company went through its accelerator program, recently used the technology at its Walt Disney World theme park. Hyp3r also claims a dozen professional sports teams as clients across three different leagues, including MLB and the NBA.

The challenge in all this is user privacy. Hyp3r only collects public posts that include a location. But not everyone realizes brands are watching. It’s easy for a well-intentioned post to come off as creepy or invasive.

“A lot of those engagement opportunities that we’re doing every day are simply liking a post,” said Glick. “That brand affirmation.”

That extends to Hyp3r’s brand as well. The relatively unknown startup is just starting to make a name for itself thanks to a growing list of customers that most people do know. When asked how big the Marriott deal was for the 23-person startup, CEO Carlos Garcia took the show-don’t-tell approach. “I think my smile will tell you it’s a company-maker,” he said.

This article originally appeared on Recode.net.