We are a CPD company with a PPC backbone. You set the price "per day" that you want your ads to sell out at. Advertisers browse the marketplace and can pickup your ad space if they think it is worth it for them. In the meantime, while you are waiting for your ad space to sell in the CPD market, PPC ads will be shown so you are always making maximum revenue. We are hoping to be a solid alternative to adsense.