Late last year Verizon started implementing a new phone trade in program that allowed users to trade in their old phones (from any carrier) for store gift cards. While an easy way to quickly get store credit, Verizon's estimates for device value were below what users could get through other online websites. While anybody could use this Verizon website to trade in your device, users couldn't get old phone store credit -- until now. In what appears to be a trial program to gauge profitability, Verizon's now offering credit up to $300 for phones in certain markets. The program is expected to last through the end of the year, and extends to residents of Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee and Texas.