BARCELONA, Spain (AP) — In the old days, U.S. wireless customers typically paid $100 or $200 for a phone and agreed to a two-year service contract. Although the phone actually cost hundreds of dollars more, wireless companies made up for it through the monthly service fees for voice, text and data.

T-Mobile decided last spring to stop subsidizing phones and padding the service fees. Instead, it lowered those fees for everyone and charged for phones separately. A few months later, T-Mobile shook up the phone industry again by allowing customers to upgrade before the phone is fully paid off.