I'm wary of using Netflix or anything similiar to it--with the sporadic ability of my local PO in efficiency I just know I'd end up on the wrong end of the stick somehow.
Not to mention I can use that money to go to a thrift store and buy twice as many books sometimes...
My friend used both BookSwim and Paperspine and compared the services. You can check it out here, and I know she'd be happy to answer any questions you have.
No, I really doubt it. I work at the public library, and am there every single weekday. They will order in whatever books I want for free, and I don't pay a penny for anything (even late fees - they waive them for staff!) I think I'm fairly set when it comes to books. ;-)
If I was in a different situation (crappier library, not working there, etc) I might think about it...