After seeing the type of ads that I was getting on my site, I decided to get rid of them altogether. I was getting a few high quality ads from places that I believe in (like Adafruit.com), but I was also seeing bottom-of-the-barrel ads that were confusing and looked like crap you might see from some third-world country. They looked nefarious and I didn't like that someone might get a virus from simply viewing an ad on my website.
So, they're gone. No more ads. I don't mind paying for hosting this site, and that was the only reason I was running ads in the first place.
If you find an ad on the site, please leave a comment and let me know where you found it so I can get rid of it. The code was spread pretty far throughout the site, so I might have missed a spot.