Preorders for the Samsung Galaxy S9 and S9+ start today and AT&T hopes its promotion will score with customers. Similar to Sprint's offer, AT&T will give customers up to $500 in account credits through combined promotions. First, customers who port in a number from a competing carrier will be rewarded with a $150 bill credit. Further, those who trade in a smartphone will receive a minimum of $200, and possibly as much as $350, in bill credits. Phones worth $350 on trade are the Apple iPhone 8, 8 Plus or iPhone X; LG V30; Google Pixel 2/XL Phones. Phones worth $300 on trade include any of the Samsung Galaxy S7 variants. With these offers combined, AT&T says the S9 price drops to as low $290, while the S9+ drops to $415. By way of comparison, Sprint is offering $350 off its S9/S9+ lease program and $150 via Visa gift card. The S9 is also sold by T-Mobile and Verizon Wireless.