A good article I wish I had read before registering my blog with Paperblog. All the reasons here:
One of the best arguments against might be that they make unsubscription extremely difficult, if not impossible. You simply cannot cancel your account yourself. I’m talking from own my experience, but not only: http://jwcooney.com/listings/
If you’re looking to promote your blog and not only its content (there is a big difference), think twice before registering with them.