https://www.gamespot.com/articles/get-15-psn-credit-when-you-spend-100-for-a-limited/1100-6457046/

Sony has kicked off another sale in the US PlayStation Store, offering some big discounts on a ton of critically acclaimed PS4, PS3, and Vita titles for the next few days. If that wasn't enough incentive to pick something up from PSN this week, the company is also holding a limited-time promotion that will get you some PSN credit when you spend a certain amount of money.

From now until March 6, players who spend $100 on PSN (not including tax) will receive a code worth $15 in credit toward a future purchase. This includes full titles purchased digitally from the PlayStation Store, as well as add-on content and subscriptions for digital services like PS Plus and PlayStation Now.