Its difficult to say because it will depend on the content and the quality of your visitors. It would be something fairly special to get someone to pay a daily rate. Typically people will pay a rate according to the number of people who click through or by the number of impressions. Usually these are in 1,000s. So you might get a rate of $35 per 1000 clicks. And then people will cap their expense too.
It is of course much simplier if you can prove you have valuable traffic and sell the ad space on a monthly basis. Ad minister will show you the impressions and clicks that a particular ad campaign gets.
But this comes with the big question of how valuable your content – and more importantly perhaps your visitors – are to a given company. This is why it would be so important for you to be able to describe your visitors – the more detailed and specific you can be the more likely you are to get top dollar!
It’s easy to see why people just stick with google adsense!!