Dear Miss Snark,
Love the blog. Read it every day, sometimes twice a day. You're addictive.
You make conferences sound pretty hellish for agents, and somewhere along the line I think you said you almost never pick up a new client at a conference. Why go at all, then? It doesn't seem like a good use of your time ... unless perhaps you have a friend in the city where the conference is, or you're getting paid real money to show up, not just reimbursement for travel.
Until the advent of the blogosphere, going to conferences was about the only way to interact with people who were potential clients and give workshops and classes on "how to query" and the like. Given this blog is less than two years old, that change over is in its infancy and many agents go to conferences to do exactly that. It's a lot more efficient to teach a class than just say "no, this isn't right" on a gazillion query letters.
Some agents do find clients at conferences. I'm pretty sure Kristin Nelson mentioned she had (but, again, she's nicer than Miss Snark, people aren't afraid of her).
I also go cause it's fun to talk to the other agents. We do have a good time at these conferences and never you mind how much gin is swilled.
And much as I complain about leaving the 212, I have seen some very nice places out in the world, courtesy of writers conferences. Buffalo. Fargo. Butte. Bumblebee, Arkansas.