There has been discussion in the past here... it works for some (including me) but not others. It all depends on the economics of your site. It is cheap enough that you can just try it and see. Good luck!
I'm running a few different campaigns and have been getting between 3-4% click-throughs. The actual price per click is between 25-30 cents, so compare that to your Goto and you'll have a good idea if it's right for you.
After doing a few sums, I would say you're pretty close. I guess it's dependant on key popularity. 'casino' keys could result in impressions of 1000+ per day pulling around 40 clicks for $10-15.
Online casinos have got healthy budgets in general and are usually comfortable paying 40cents /click, they tend to get their money back easily from their visitors who are looking to play, but small businesses would maybe suffer from window or comparison shoppers who aren't planning a purchase.
I guess I will give my clients the option, but not push it.