During the 8 week promo, I thought about buying a subscription but went with an enhancement.  I am a really small company ( one county).  My income is usually allocated before it comes in.  It is a reasonable monthly fee, but I don't need all the features.  Maybe if there are enough other people missing the articles and information sources you could offer another product that just serves availibility to the articles ( in the future).  Or "Enhanced Plus"....charge a little more and give access to the articles.  Another tier in the product ladder could offer more revenue return for the site. 
Thanks for your time and consideration.  You all do a great job and I am really happy to have found this site.
Kim