Think twice about setting up a Foursquare campaign for your next client: location-based services don’t provide more than a “minimal” impact on the bottom line, according to data obtained by Fast Company.

In fact, a successful promotion from Yelp, Foursquare, Facebook Places or Opentable Spotlight usually provides about a 2% increase in revenue.

The company that provided the data, Applied Predictive Technologies, is a software firm that uses analytics to conduct studies of the effectiveness of social media campaigns. Senior VP Jonathan Marek told Fast Company that he was optimistic about the potential of location-based services, even if they haven’t yet proven themselves: after all, there’s little risk or up-front cost to offering a check-in deal.

“It’s still a pretty nascent space,” Marek told Fast Company. “I don’t think anybody has gotten the model right.”