Postpaid plans can be pretty easily upsold on other non-minutes/non-data expendables (like upgrading a phone), which then further help to 'lock in' customers. A

Postpaid plans can be pretty easily upsold on other non-minutes/non-data expendables (like upgrading a phone), which then further help to 'lock in' customers. Although I think most of all is just the history of how the phone industry has evolved its plans: postpaid is an evolution of contracts, so everyone sees it as a more consistent flow than prepaid (which has the legacy of burner phones/plans; that $40 this month does not guarantee $40 next month in the way that postpaid plans do).