BARCELONA—A lot of people know foursquare as a check-in service, but during a keynote at Mobile World Congress (MWC) today, CEO Dennis Crowley said it's a lot more than that.

More than 15 million people have checked in someplace around the world, proving it's not just a service that's been popular in urban areas of the United States. Dots on international maps showed foursquare lit up all over the world.

The CEO said Act 1 is about recycling data; every time someone checks into a hotel or restaurant, foursquare learns things about what that person likes to do and starts to figure out people's behavior patterns, whereby it can then make suggestions and/or let people know what nearby sites their friends might have recommended. "We're enabling people to cut through this data stream" in a way that nobody has done before, he said.

He also talked about enabling people to learn recommendations from their friends, such as the best hidden gems of snow powder at a ski area, so when a person is at that area, he or she can get notified that one of the areas is nearby. Similar use cases apply to merchants.

For Act 2, he showed a picture of people lined up, all of them looking down at their phones, similar to what a lot of people are doing at MWC. People are conditioned now to ask questions using their smartphones – whatever they're curious about at a particular time. What if you could take the old Microsoft Clippy and make it smarter, so that it lives in your pocket? The phone can remember that you told it how you like something and the next time you're in the vicinity, it will send you an alert letting you know your preferred type of food or clothing is nearby.

Crowley was being careful not to give too much away about what foursquare is doing, but he tried to give some examples – some that might sound familiar to people in the wireless industry. For example, if the phone knows you landed in Barcelona, it can let you know if friends also have landed and start to recommend places to visit.

Crowley, who sold Dodgeball to Google in 2005, ended his keynote by saying he hopes to return next year to give an update on all the things the company has accomplished. Stay tuned.