ReadWriteWeb has some discussion. I’m not very impressed I have to admit. I don’t see this working, but give it a look for yourself.
On the other hand
I do like both of these efforts for the very interesting Exact Editions:
Sawdays have launched digital access to their books via Exact Editions Book Publishers Platform. I rather like the way it looks and access for a year is very reasonably priced too.
And Exact Editions also launched access to Debrett’s Peerage & Baronetage as well. Again, the pricing is reasonable.
As a general point, the reasonableness of these online access prices makes a mockery of some of the e-book download prices I’ve seen.
Worth checking out all three, but if someone can see the first working, write and let me know how!