If I remember correctly, the admin of this site said that this is the only Q & A site that is also a profit-sharing site with Google AdSense, so yes it is a new concept in that sense. No, it wouldn't be new with the questions and answers part, but it is unique in its own way!
I really don't know who is the first person to join, but I assume it was sidelko (admin) who joined on November 19, 2007. His member number is 424242, which is the lowest one I could find on the leaderboard - and yes I realize that's a weird number to start of with. They may have used the same system as with another site for the member aspect for this site, so it just continued on from there.
The reason Yahoo Answers doesn't do anything like this is something you'll have to ask them. I suppose they assume that people will just use their site and that is good enough, while Yahoo gets paid all of the royalties for advertising. Usually, larger, already established websites don't need to do something like WebAnswers because it already has the internet traffic and is a well-known name.
However, with that being said, I truly love this site, and it is something to stick around with and use for a while. No, you won't make too much at first, but little by little, with each answer you put down you will be making more and more until you get enough to pay off a bill every month! Good luck and just remember to answer all that you can with your best answer, and never ever click on your own ads!






