Well ... as to what it does, MobileRead is a community of electronic book aficionados. We talk about books, we talk about ebook readers, we talk about software, and we argue about just about everything. By and large we're a very polite bunch (except for me).
One thing we don't talk about, though, is where to get pirate copies of ebooks. Ethical issues aside, that could get MobileRead shut down, and possibly get the fine folks who run it in grief. The kind of grief that involves expensive lawyers. We don't want that to happen, so we (except, obviously, for the OP of this thread) don't promote sites that offer illicit ebooks.
There is a difference between one person lending a printed book to a friend and a website giving infinite numbers of that book to all comers. A printed book is sold as a physical object -- you can read it, sell it to someone else, prop up the corner of your couch with, whatever. And, much like the plate I'm eating my breakfast off of right now, once it's sold, the manufacturer is pretty much done with it. Also, it can only be in one place at a time. If a hundred people want to read it, 99 of them are going to have a long wait. Ebooks, on the other hand, can be replicated indefinitely. If everybody just shares copies, how is the author going to make enough money to buy her groceries and pay her rent? I've met quite a few authors over the years, and not a one of them could subsist on dewdrops and moonbeams (beer, possibly). The ones I've met have all been good people (except for Larry Niven, who is a donkey). They need their rent and grocery money, too, just like the rest of us. If we all just downloaded illicit copies of their books, they wouldn't be able to buy their groceries (except, again, for Niven, who's independently wealthy, which may be why he is a donkey) and would have to do something else for a living.
If I want a book bad enough, I'll buy it. If it's not worth six bucks, or ten bucks, or whatever, to me, how can it possibly be worth my honor, which is much more precious? It doesn't matter if nobody else knows. Your reputation is what people think about you, but your honor -- your character, if you prefer -- is what you are. It's definitely not something you want to trade for a badly-scanned copy of Twilight.
Mostly, I read public domain stuff -- books that are long out of copyright. For one thing, they're free. For another, they're classics for a reason -- nobody bothered to save the books that sucked. So if you dig around somewhere like Project Gutenberg, you're getting the cream of the crop for hundreds of years of crops. A hundred years from now, I doubt if anyone is going to remember much, if anything, on this week's NYT best seller list -- but they'll probably still be reading A Tale of Two Cities. MobileRead has a good selection of PD books; if I want something that's not here, I try ManyBooks, Feedbooks, and Project Gutenberg (in that order). If none of them have it, I move on; with tens or hundreds of thousands of books at my fingertip, I'm not too worried about any given one.
Then there are the authors and publishers who tempt us with free samples. You'll find links to a lot of them in the "news" section of this forum. The idea, of course, is just like any other free sample: you'll like the first book and buy the rest of the series. Baen Books is particularly insidious that way. *sigh* And my quick check to see if there was anything new up just cost me twelve bucks ... I have GOT to stay away from that place. BookView Cafe is another favorite of mine (and if you're checking it out, and you like mysteries I can't recommend
Lacing Up For Murder highly enough -- it's absolutely excellent). I've gotten a book or two from Lulu, and a few technical titles from O'Reilly. Smashwords is pretty popular around here, too.
With so many legitimately free or cheap ebooks out there, who needs to get them any other way?