It’s a beautiful summer afternoon at your favorite ballpark. Before you get to your seat in the nosebleed section, your iPhone alerts you that better seats are available — for a price. Sound too good (or annoying) to be true? Not when Apple’s iBeacon technology is at work, according to Businessweek.

Offering seat upgrades is the latest example of how the new indoor mapping technology is being used by stadium and arena owners. In this case, visitors to the Oracle Arena in Oakland, Calif. are receiving “a friendly suggestion” from their phones when they step off the escalators. The arena is home to the Golden State Warriors, the first NBA team to use Apple’s iBeacon technology in this way.

Sonic Notify, the company behind several dozen 2-by-2-inch beacons in Oracle Arena, believes sports franchises are the ideal business to use the technology. Unlike shopping centers, which have to worry about annoying their shoppers, “You’re not going to get mad at the Golden State Warriors and go to some other arena instead,” says Aaron Mittman, the company’s chief executive officer.

According to the report, “The idea is to boost demand by capitalizing on another tech craze working its way through professional sports: the use of cheap sensors to track people’s exact location within the stadium.”

First introduced in 2013, iBeacon is an indoor positioning system that enables an iOS device or other hardware to send push notifications to iOS devices within close proximity. The technology uses Low Energy Bluetooth (BLE), also known as Bluetooth 4.0 or Bluetooth Smart.

Apple retail stores are already using the technology to provide customers with detailed information on products as they walk by. Many MLB stadiums will be equipped with Apple’s new iBeacon when play begins in April. In doing so, attending games will become “a completely interactive experience for fans.”

The NFL also used iBeacon during last February’s Super Bowl around New York’s Times Square and at MetLife Stadium.

For more on iBeacon, see: Apple Rolls Out Its iBeacon SpecificationPhilips Planning Its Own iBeacon-Like Connected Lighting For Geo-Mapping Stores, and Shopkick’s iBeacon Trial Will Grow To 100 American Eagle Outfitters Stores.