It's a fine line. Paraphrasing is generally o.k., but reproducing big chunks can raise ire. I hope that Mr Fish and McGraw-Hill didn't get feathers ruffled by a recent post of mine, in fact. At least I went to the trouble of typing it in, rather than scanning. And I plugged the thing too.
But books and other articles, papers, etc. are a lot of work, and I can understand the concerns of authors and publishers.
Personally, I'd be more motivated to seek the given book out, having read that excerpt. But then I buy a lot of books. As a result I'm often broke and running out of space, but you have to keep your priorites in line.
I suspect the Google practice is working to sell more books than not---they entice you with fragments. Sometimes your specific question is answered, but you can also see that there is much more material not shown. I looked at a collection of papers yesterday, about ferrite behavior, and there were convenient links alongside to purchase the book. I was tempted, although it was a bit too pricey for current financial conditions.
The book rental services are interesting. I don't know how well they are doing though---the prices seem mighty high. I guess they are primarily targeting students, who in many cases want to get rid of the damn things the moment they pass the course. I hope there's a yellow highlighter penalty clause :razz:
BTW I was alluding earlier to the anecdote in which a man walks up to the notoriously laconic Coolidge and says "I made a bet with a friend that I could get you to say more than two words to me." Coolidge: "You lose."
