Bing starting a new 7–day “Bing cashback Twitter Sweepstakes,” from July 23 on Twitter, @bingcashback. The contest runs each weekday until July 31. Each weekday, a new Bing cashback- trivia question will get tweet. To enter, reply to @bingcashback with your answer and tag your tweet with #cashbackpack within one hour becomes eligible to win. No purchase necessary. Open only to legal residents of the 50 US and DC 18+. See official rules below. Bing is giving away SEVEN $500 Visa cash cards, each in cool Bing backpacks. The lucky winners can use their cash card to take care of all their back-to-school shopping – and what better place to find great deals than on Bing Shopping and Bing cashback!