Basically people buy a tonne of $1 domains (.info) with a catchy url. They trow up a free script and template, add adsense.

Then simply submit it to proxy lists and spam yahoo groups. Just one of those proxies will make at least $5 usually within that month, if not more.

Proxies are so easy to make, you could setup and promote 5 every hour.

if you own a network of 200 proxies that get good traffic its easy $xxxx a month.