Re: Not a writer's Bible
] Think of Writer's Market as paid advertising by the agents.
I'm not sure I understand this. You don't have to be paid to be listed in Writer's Market. My magazine is listed in Writer's Market, Poet's Market, and Short Story Market, and I certainly never paid a dime. I assume agents don't pay either, but correct me if I am wrong.
All the Writer's Market publication do is collect information via questionnaires from markets, publishers, and agents, and make it available. They don't vouch for anyone, although they will remove an entry if they receive enough complaints of misrepresentation. So, if you found an agent in Writer's Market you think was a scammer, be sure to contact Writer's Market and tell them so that it can be removed from future editions. The editors rely on information from publishers, editors, and writers to compile this thing.
I do find the Market books are often out of date. That is partly because the publishing world is in constant flux. And, it is partly because the guides come out too early in the year--the 2005 edition, for instance, comes out in September of 2004. As an editor/publisher, I find this doesn't really give me time to update my information for 2005, since most changes occur toward year end.
Having said that, I still think these are the best resources available to find a wide array of markets.