Well, almost no-one! 
Check out the latest stats from Mike Liebner…
Last month data (as of today):
December 16, 2006 350 set 1 191
December 16, 2006 350 set 2 133
December 16, 2006 350 set 3 121
So, of the 350 people who are entitled to download each set, less than 150 people on average do. For one set, only 121 people downloaded the articles!
… and that’s only counting the downloads. How many people who download the articles will actually do anything with them… like build a website… and then promote that website?
My guess? Almost no-one. 
That means next-to-no search engine competition for these articles. So that’s 400 articles which almost no-one uses, for $97 per month. If you’re looking for content, this is a true no-brainer. Especially when you consider the excellent blog announcement system Mike lets you access for free to promote your sites.