I was making a few thousand dollars a month from a coupon site. The Panda update completely knocked me out of the rankings for the past 4 months, but I've been slowly climbing back up on my top keywords. It was literally no work whatsoever - I wrote a script to aggregate coupons automagically and outsourced SEO. Turns out the latter wound up killing me. (If you're an SEO master, please reach out to me on Twitter) :)