I hate those printed coupons that come along with my grocery receipts. They’re too easy to forget or lose and too hard to redeem. I also hate loyalty cards, mail-in rebates, and all the other tricks ...

While they may not be the all-in-one solution some had envisioned, QR codes are still very popular. It’s easy to understand why, too — just point your camera or scanner at a QR code, and you’re ...