The online game Etymologic bills itself as "The Toughest Word Game on the Net!" I don't know about that, but it is addicting, and lots of people think so too. When you arrive at the site, it tells you are the 134545939 person who has played the game. That's a lot of hits.
(Left: And our next word is zeugma.)
So far I have played four times and have an average score of 8.25 out of 10. I think that's pretty good, but Etymologic calls anything from 7 to 9 "Good!" Is that enough praise for getting the majority right on the toughest word game on the Net? I think 7 should be magisterial! 8 should be scintillating! and 9 should be consummate!
There's only one snag with this game. There are not enough questions to guarantee that you will get different questions for each set of ten. Out of my forty questions, I had at least three repeats. That skews the scores down, and makes me less likely to come back in the future.
Now you do have an option to submit your own question, to build up the question base.
But here's my suggestion. Hire me to write questions at $9.95 a question. If Etymologic.com has 134596754 hits, then the Google AdSense revenue has got to be through the roof. This investment would pay off in bringing back more repeat business, as players would feel confident that they would get new questions every time. And the questions I would write would be tough but fair, with imaginative wrong answers.
Who says humanists can't succeed in the private sector?