Business owners might appreciate an opportunity to be part of a feedback loop they can generalize - say greater than 30% discount just isn't possible due to cos

Business owners might appreciate an opportunity to be part of a feedback loop they can generalize - say greater than 30% discount just isn't possible due to cost structure (group buy won't matter)- let them indicate that somehow for their business to filter/feedback future requests, so they don't feel like they are getting bullied with a lot of requests greater than that. For users, maybe let them also offer non-monetary factors for discount - off-peak / non-prime hours, introduce a friend, available on short notice to fill a cancellation, post a blog or tweet, post a local sign, ??, etc. - bartering a little for the discount where the retailer would see value in the barter. Groupon can't do this, but your personalized approach seems ideal for this. In cases where business finds deals that work, archive them for the business, then offer to post or syndicate them on-demand as desired by business to drum up demand on an ongoing basis. And to keep users interested, do something where you as the service do random (or not so random) selections and 'make the discount' happen for the requester, at _no_ cost to the merchant.