As per my other comment, I've considered it, but haven't gone thought with it. My only motivation for the site was to repurpose what I had laying around on my hard drive in hopes it would be useful to people. Also, I wasn't willing to do anything that would sacrifice experience or quality, so I decided not to.
Only thing that I think could work would be approaching android devs directly about ad based sponsorship, because that would allow me to control the relevance and quality of the ads. Decided against it as, honestly, I'm busy with other things and the hassle outweighs any potential revenue I could hope to get out of it.