SignalAd is a fast growing matchmaking community for advertisers and publishers.
You could start your campaign with SignalAd choosing either direct ad with a specific affiiate web site or to start a network campaign. There is a fixed price for direct ad determined by the affiliating publisher which can be CPM, CPC or pay-per-day. Network campaigns will be set up at the publishers web sites who agreed to accept network campaigns. You can place a bid for network campaign either CPC for text ads or CPM for a particular banner size. You can target your campaign by country, state, week days and hours for network campaigns. And determine daily budget for network campaigns.  You wouldn`t lose your traffic on Saturday night with usually lowest conversion or whatever you found the worst time for your campaign.