Samantha Daniels, president of Samantha's Table Matchmaking, said that millennials' noncommittal nature has shaped the way they approach their offline social life, and Grouper is tapping into that shift.
Grouper said users also have made romantic connections through the more informal group gatherings.
"Most of the time, people want to meet people through friends—there's a comfort level," Daniels said. "The success rate may not be as high as a more traditional way of meeting someone. But like my grandmother says, 'If you're invited somewhere, you should always go.' You never know what's going to happen."