I recently came across a Capital One program called Spring that offers Dell shopping discounts, Priceline discounts, and deals from quite a few other merchants. You can sign up for free, and you do not need a Capital One credit card. According to reports from readers, the Priceline discount is pretty strong and appears to be a real discount, without the usual issue of prices being raised first and then discounted.
That said, after looking through the merchants, it seems that many of the offers are mainly geared toward small business needs. If that sounds useful to you, it may be worth a look.