It looks to me like they just get paid to get volunteers to work. Nice
scheme. So it's not technically paid editing :)
"WikipediaExperts is a fast-growing network of experts which includes many
Wikipedia editors. When a new assignment arrives we send it to the editor
whose profile is the best fit with the subject of the article. We also
provide support for pro-bono work of the participating editors."
--
~Keegan
http://en.wikipedia.org/wiki/User:Keegan