Ask HN: Any ethical, non-tracking advertising services that are decent?

I'm getting ready to release a project that I've been tinkering on for a while, sometime in the coming weeks.

Ever since the whole NSA debacle started, I've been trying to shift towards a free software lifestyle as much as possible. I want what I'm working on to be RMS-approved, but I also need some form of revenue to keep the servers running. This puts me in a bit of a predicament because a lot of advertising solutions track user actions and contain non-free code, and that's something that I don't want to subject my users to. So are there any good advertising networks that, at the very least, don't track user activity?

I realize that "the cloud is a trap," but I don't think a weather forecasting service would make much sense in any other context.