Ask HN: Why doesn't GitHub use the free impressions to sell ads?

Github is getting a huge number of requests to execute javascript on host pages. Injecting an advertisement for Chinese reading expats seems like a fantastic use of that traffic. It both helps defray the cost of bandwidth, and also discourages that type of attack.

I don't know what headers they're receiving, but i'd guess the search terms are included. How much would you pay for complete control of 0.01% of google's search results?