If you can drum up enough coverage, it works quite well. The key is getting coverage - the more people know it's up for sale, the more people will bid.
Edit: just to clarify they are referring to things like "eBook teaching you how to make $1,000,000 a day by doing nothing!" type sales
That said eBay is specifically referring to the type of digital good that can be duplicated endlessly. A website is a single thing. You can run the software that runs it on another domain but you are not duplicating the site itself. Which is why I don't believe it would run afoul of this rule.
Try this site http://www.codango.com/, you can list it for license there. This way you can license it over and over again I believe you will make more this way then a one time sale. If you get a good base of people who have licensed it, you can create upgrades for another thing to sell.
forums.digitalpoint.com
Those are two of the biggest out there for selling developed sites.
It is not beRecruited.com (http://www.berecruited.com) - which is doing quite well!!
It's a side project that I worked on called PopChatter (http://www.popchatter.com) - which was more of an experiment in Ruby on Rails than anything else. I simply don't have enough time these days to grow it and innovate (just not enough time in the day!).
Good luck with that.