First off let me say I have no horse in this race (I'm not a Scribd subscriber and I'm not a romance lit reader
). It's interesting to read that blog post. It looks like they are hoping to rotate enough books thru the romance section to keep those subscribers but at a reduced number of books read by each of them. Sounds like they're hoping to have enough to keep them by being just part of the source of material for those readers -- i.e. they'll maybe read one or two from there and get the rest of their monthly fill elsewhere, and be willing to come back the following month for the "new" selections rotated back in, repeat ad nauseum. That seems slightly less ridiculous than just cutting and hoping no one notices and cancels (but only slightly).
Obviously their model relies on a large number of subscribers that don't actually read enough to cost them more than they collect from them. I'm not sure I buy that this as a realistic long term model.