Getting a speaking gig at Pubcon is only the first step. Once you have a slot, you want your session to rock, but no matter how awesome your presentation is, if no one shows up to hear you it doesn't matter.
Brett gave me my first shot speaking in Boston the week my book came out in 2006. I think I started doing SESSION CARDS ON THE BACK OF MY BOOK BUSINESS CARDS right after that.
When you meet someone at PUBCON, it's easy to say "Come to my session," but how will they remember? No one is going to remember that you speak at 10:15 tomorrow morning in Salon A. Enter session cards.
Session cards not only tell folks when and where you're speaking, they also advertise the other peeps on your panel.
I usually print my show-specific cards literally right before I leave for the airport because I own a copy shop. This time I decided to actually get my show cards printed at a REAL printer! See y'all at the show!