As you probably know, advertising networks like Google AdSense charge
considerable commission fees from the funds, paid by advertisers (commission can even reach as much as 50%).
From the other side, some large services with heavy load and big maintenance expenditures like Wikipedia rely 100% on the donations from its users.
I have an idea to create absolutely free ad network where publishers will receive 100% of the funds, paid by advertisers. To get enough funding for the hosting and other costs (which unfortunately becomes very tangible with service's growth) I am considering to offer service's users to select a percent, which they are ready to donate when making a withdrawal.
Do you think this model is viable?