Does anyone know who provides the bulk of the ads on these re-direct/ad DNS servers that ISPs are using these days? My guess is it's probably not Google or why

Does anyone know who provides the bulk of the ads on these re-direct/ad DNS servers that ISPs are using these days? My guess is it's probably not Google or why would they offer an alternative? It sounds like a very clever way to attack their online advertising competition to me. Obviously they'd get into some hot water by trying to compete directly with their own advertising based DNS. Instead they attack the entire market of re-direct/ad DNS by offering a clean alternative that happens to hurt their competition. Very clever. It wouldn't surprise me to see some of the Google software (Toolbar, Chrome, Notifier) offer an option to use Google DNS in the future. For the end user it's a good thing -- for Google's competition it's pretty terrible.