Big Dance, big money?

While most of us will be keeping a close eye on the Final Four scores this weekend -- and the national championship game Monday -- Square will be paying attention to a different kind of result: money spent in Atlanta while the tournament is in town.

Founded in 2009, Square produces a free credit card reader that plugs into iPhones, iPads and Android devices. It makes its money from the 2.75 percent transaction rate it receives with every swipe.

The company will be collecting data from more than 50,000 individuals and businesses in greater Atlanta using the reader, which lets them accept credit cards anywhere, anytime. For this weekend, think food trucks, livery cabs and street vendors shilling Final Four T-shirts.

Square has tracked spending during another big sports weekend. This past January and February, it measured economic activity in New Orleans during the Super Bowl and produced cool heat maps showing how much economic activity spiked around the Mercedes-Benz Superdome.

Comparing data from Super Bowl weekend and the weekend before the game, Square found that on Super Bowl weekend the number of items sold increased by 14 percent, while total commerce among its 10,000 users there increased by 60 percent.

Drilling down further, Square discovered music and entertainment vendors did eight times the business they did the weekend before the game. Meanwhile, taxi and limo drivers nearly tripled their business, while retailers saw sales nearly double.

There were a few quirks in the results. While the most successful Square merchant in New Orleans over Super Bowl weekend was a sports memorabilia vendor, lattes were the top-selling item in New Orleans over the weekend. That's right, lattes.

Of course, these numbers are small potatoes relative to total business for Super Bowl weekend, but that figure is hard to quantify. Square's numbers are real and link a big sporting event to local economic activity.

One day, league officials and city leaders may use Square’s data to make their case to taxpayers that the expenses of hosting a big sporting event are worth it. But not yet. The company says data from just one Super Bowl or Final Four weekend isn’t enough to say one way or the other whether such an event really boosts a city's economy. But if patterns emerge after two or three Super Bowls, Square might have something.

Until then, the data will be a lot like this year’s NCAA tournament. Largely unpredictable.