I've been on there for about a month. Here's how it all works: (Man, this is gonna be a long-winded post... ugh)
The Mechanics of Authonomy
The purpose of Authonomy is to get your book into the top five spots so the HarperCollins editors will review it. When you first sign up, your rank will be in the 7000 range. (Mine's up to 166.)
For your book or partial to be visible on Authonomy, you must post a minimun of 10,000 words. Most people post 3-5 chapters, but some post the whole book.
If you decide to post something, post it at the same time as you sign up, never a few days later. NEVER. More on this below. Once your book is posted and you have clicked the button to make it visible to others, never make it invisible or you'll lose your spot in the ratings. Also, never let your word count fall below 10,000 because that'll make you lose your spot, too.
Your book has a rating and you have a personal score called TSR - Talent Spotter Rating. You want this number to be as small as possible. When you start, your number will likely be 11,000-ish. Mine's 31. The TSR score, along with the number of books you back, the number of backings you get and the number of comments you leave and get back somehow work together to determine your book's rating. No one can figure out how exactly this works.
To get your TSR score up (see below) you have to back a book with a low rating that you think is really good and will climb the charts. BUT, everyone who wants to boost their TSR fast will back the newest books. If fifty people back a book in less than a minute, the TSR of the first ten or so of those fifty people will skyrocket. Savvy users *cough* are always looking for new writers to back their book right away, whether it sucks or not. This usually propels a book up to 2000-something from 7000-something. If you sign up for an account, then ignore it for a week before you post your book, your profile will be so buried that you won't get that boost because the hoard won't back you en masse. And frankly, if you're starting from 7000, you'll never make it to the top five. Really you won't.
The Social Aspect of Authonomy
Most people on the site are mean. Really mean. The site has no visible moderation and people will say the nastiest things in the forums. I mean, I've seen the n-word in there. Yeah... the n-word. You can report abuse, but nothing ever comes of it.
There are two warring factions on the site; the group that plays "the game" and the forum-dwellers. The forum-dwellers spend most of their time complaining about the players. The players are on the site to get to the top five - they don't care about anything else. The forum-dwellers (aka The Whiners/Moaners). The forum crowd say that they're there to "improve their craft as artists," which is all well and good, but I don't think that most of them do any actual writing.
Some "people" on the site are dummies... you know, like in a department store. Some people have secondary accounts (called sock puppets or socks) to offer extra backings to people who back the writer's book. It's not really considered cheating, but a tool to win the game. The forum-dwellers hate socks and I can understand why - right now two of the top five TSR scorers are socks.
Socks are just one of a few tools (I don't use one, btw) that the players use to climb the charts. They also spam and nudge like crazy. Authonomy actually seems to encourage this. I read somewhere that they like an author who's good at self-promotion. *shrugs* Authonomy also encourages people to get their friends and family to sign up to back their book.
The "Scam" and Stigma of Authonomy
HarperCollins advertises their self-publishing business on the site. I assume they must make a lot of money from people with poorly-written novels and poetry books who desperately want to be published. I'm not trying to be mean when I say that - it's the truth. I can understand that everyone has dreams - I'm not begrudging anyone of their dreams - but... I feel like such a meanie... not everyone who writes a book is going to be offered a contract from Random House. Querytracker is VERY different (and considerably better) than Authonomy - pretty well everyone on here is fairly serious about getting published. Authonomy isn't like that. A lot (most?) of the books on there stink and for some of those writers... well, self-publication is probably their best bet.
A lot of writers (including some folks on here) hate Authonomy because of all of the "problems" with it. (Socks, masse-backings, people backing a book without actually reading it, etc.) I see their point. As I said in another thread - Authonomy has no dignity and serious, dedicated writers are by-and-large disgusted by it. But you have to take it for what it is - a game. You can play or not play. I'm playing. I know that 99% of people who back my book aren't reading it, but I don't really care. I just want the critique from the HC editors because I think it'll be useful. AND there is the very real possibility of being picked up by an agent. The guy who's currently in the #1 spot got an agent when he was in the top fifty.
"Problems" with Authonomy
People back books without reading them
Mean people in the forum
You don't need to confirm an e-mail address to sign up so people can sign up with fake addresses and back their own stuff easily.
Generic reviews. Ex: Wow! What a page-turner! You have such a gift for writing narrative! I just love how you introduce your characters - you've made them so real and the dialogue is excellent... blah blah blah.
People back books that aren't fit to line a bird cage just to get a return backing to boost their own rating, which means that really crummy books can make it pretty far - not that HC will publish them, of course.
Masse-backings, not backing anything with a red arrow even if it's the next MOBY doodle, the ability to back unlimited books, and umpteen other things that you can do to boost your TSR score
I could go on...
If you're serious about playing, you need to keep track of everyone you back and everyone who backs you on a spread sheet.
Leave a comment for every book you back as it'll boost some mysterious mechanism in the scoring.
Back new books everyday, preferably several times a day. If you don't log on for a week, your ratings will fall like a lead ballon. You've got to keep at it.