I have a campaign going now since the autumn and I average 1100% ROI.
yes, 1100%. I'm being drastically undercharged for clicks (few cents CPC leading to a site that sells products for 50-60 bucks) and feel almost guilty about it.
Almost.
As usual with these things, if only I could get 10 times the traffic, I'd be retiring by the end of next year. :)
Tell me tales of pots-of-gold-at-end-of-rainbows ad campaigns you've run.