What is the best way to handle the invoicing for "sponsor" ads? Do you just set a CPM price point and just track impressions and send out an invoice for each month? It seems like it works the same way as an ad network at that point. Isn't a sponsor more than just a label for an advertiser?
I already have "sponsorship" ads in addition to ads served by an ad network. I originally just agreed to run each sponsor's ads on every page for a certain length of time (1 month, 1 year, 6 mo etc), which I now realize was not scalable. However, I'm thinking I can just ask the sponsors' permission to modify their existing deals at a specific date so that their ads continue to run until the ad has been served the same amount of times I originally promised. And new sponsors after that date would pay for a certain number of impressions.
But is this the normal approach taken on sites that use "sponsors"? For example thedailywtf.com. Did I do this right?