Starting today, iPhone users can join the Apple iPhone Upgrade Program even if they're buying online. Until now, the program was only offered as part of an in-store purchase.
The iPhone Upgrade Program allows you to essentially lease a phone from Apple by paying a fee each month. After a year, you're eligible to upgrade from your current model to whatever is the most appropriate new product.
Online membership is not available to everyone on every carrier yet. Eligible AT&T, Sprint, and Verizon customers can start today online but T-Mobile customers still need to visit a store for now.