Here's a memory hook:
- "ou" because that's french for "oo", as in: douche.
- "l" since it comes from "roule" or "rouler", as in: joule, boule (there is no "ll" between "ou" and "e" in french, ever).
- "tt" since it's a female noun, as in: cassette, baguette, couchette.
Keep the main application advertisement free, but buy up all the doppelgangers and advertise on those.
Diabolical.
Every time a user, or potential user, mistypes your URL then best case they end up on some keyword related site. Worst case - they end up visiting some adword-buying competitor.
If it's more profitable to direct users away from your site than to visit there's a problem with your business model.
Having shamefully owned a few typo domains in the past, I can confirm this is true. The ad click-through rate on typo domains is absurdly high (~33% IME), probably because the ad is for the domain they intended to visit.
One interesting sidenote: the word "roulette" is terribly hard to spell. Pretty much every typo domain for it got snatched up pretty quickly, and are currently showing AdSense for domains. (chatroullette.com, chatroulete.com, etc.)
Probably making a solid amount of money. I hope the owner himself is the one sitting on them.