Robin Good's insight:
Switchads is an automatic auction ad platform that allows you to have multiple ad networks compete for your the minimum CPM price that you set.
For example if you are running Google ads on your site you can activate SwitchAds easily and your Google ads will be replaced with alternative and higher paying ones, only if there are advertisers meeting your minimum set CPM.
In their words: "Using SwitchAds unique technology, we provide your website with access to increased advertiser budgets by getting them to bid on your inventory in an auction. This increases the competition and price for the advertising on your website."
In this way your risk is zero and you can only possibly gain some extra revenues.
Switchads makes money by adding his small commission on top of your minimum set CPM revenue.
You can check stats and revenues in real time.
N.B.: I am currently testing Switchads on the top banner space of MasterNewMedia but I have too little data to yet express an evaluation.
The only drawback I encountered has been setting my minimum CPM in British pounds.
Free to use.
Try it out now: http://switchads.com/
How it works: http://switchads.com/index.html#how-it-works