Just a week ago, Microsoft launched a limited-time trade-in promotion, allowing users to get a minimum $200 gift card for trading in an iPad at one of Microsoft’s brick-and-mortar stores. This week, Microsoft has upped the ante on trade-ins involving its competitors’ devices. Users can trade in a variety of phones, tablets and PCs, including Apple iPads and iPhones, Samsung devices, BlackBerry phones and more and receive a gift card worth up to $350 via a new Microsoft Corporate Buyback promotion. (I’m not sure if Microsoft just launched this program on September 18, which is the day Apple launched iOS7. I learned about the new promotion via a September 18 blog post by a Microsoft technology evangelist, however.) The frequently-asked question (FAQ) section of the new promotional site says it is open to anyone.