I say go for it. It's a bit like Amazon's excerpts and "search inside" feature- I think it actually helped sell books. Publishers should be
happy.
And I would be quite ok with a paying service too. Too many times we (me and friends) found ourself with a book we can't find at the library but just on google- and, of course, just a small part of it. Plus it would be a pdf or a proper ebook- don't care, as long as we're able to put our eyes on the text
