Twitter also makes money off cell phone data. Notice they both now require you give them a mobile number and they suggest you Friend people who you know personally. It's because their apps upload all your contact numbers into their databases and they cross-reference everyone's numbers to see who knows who. They create detailed marketing data based on the combined info that everyone gives them and on the GPS location data that their apps transmit to their servers when you have location turned on.
Twitter also makes money off cell phone data. Notice they both now require you give them a mobile number and they suggest you Friend people who you know personally. It's because their apps upload all your contact numbers into their databases and they cross-reference everyone's numbers to see who knows who. They create detailed marketing data based on the combined info that everyone gives them and on the GPS location data that their apps transmit to their servers when you have location turned on.