I’ll also add that spending habit data is very valuable in terms of advertisement. We are in the age of very targetted advertisement. Just a random example: *user14555* on our T-Mobile app eats at a restaurant for lunch every Thursday. Have the app pop-up with a coupon from one of our participating restaurants on Thursday morning.
Restaurant will pay or give exclusive coupons to T-Mobile in exchange for these benefits. T-Mobile then hopes to entice more users by listing their app and “exclusive coupons” as unique benefit to using them as a cellphone provider. All the major providers have more or less settled at similar prices for cellphone plans so they lean on these extras as marketing tools.