Sports teams are exploiting the growing installation of inexpensive sensors to track fans' whereabouts in stadiums to boost demand for more costly upgraded seats by sending suggestions to fans via their smartphones. Sonic Notify CEO Aaron Mittman says sports franchises are perfect for using such technology, whereas Macy's and other retailers risk irritating shoppers with messages. Sonic has installed several dozen sensors in Oracle Arena, which is home to the National Basketball Association's Golden State Warriors. “You’re not going to get mad at the Golden State Warriors and go to some other arena instead,” Mittman notes. Still, it may take awhile for teams to bolster their revenues in this way. For example, the National Football League ran a test to see how people were using arena Wi-Fi networks last season, only to learn they were mainly uploading photos to Facebook. Moreover, it is unlikely that most Golden State fans will get such notifications for the time being, as Sonic Notify estimates that less than 30 percent of people with Bluetooth Low Energy-equipped phones keep the feature activated regularly. In addition, the team simply does not have enough tickets to go around, since the franchise's Kevin Cote reports the Warriors seldom have more than 50 extra tickets available per game because the arena sells out nearly every night.