Show HN: PassStack - a place to share Passbook coupons and deals

One problem with Passbook right now is lack of content. A dedicated website for Passbook coupons I think makes a lot of sense, but the challenge is to educate businesses about the usefulness of Passbook. I talked to a restaurant owner yesterday and showed him Passbook (on his phone, but he had no idea what it was) and he was quite excited for the opportunity. I wonder how this could be achieved in a wider scale.