Yes, very clever! Is there any chance you would offer 2 or 3 different themes? I recognize that some users may like the look of the site but how about an option to select another theme for those of us who enjoy the quality of the search results but can't stand the range of colors and font style?
Out of curiosity, how does duckduckgo make money? I _never_ see ads (a good thing, but I'd love for the service to continue, so hoping that you're making money somehow!)
Ads have been on and off, but subtle. There's an issue with the ad feed that I was using that caused me to turn it off for a while. I've been so busy I haven't fixed it, but I'll get to it soon :).
There's a bunch of easter eggs in there, e.g. search for cuil.