#2 is crucial. I've exhibited at events where almost no one was buying technology. Worse, many of the people who stopped by and seemed interested were not people who would make software decisions for their organization.

You have to do your homework. Go beyond reading the event's website and literature. Just because it seems like the right crowd for your product doesn't mean it is. Or maybe it is, but the tradeshow floor is in a weird spot or only open during lunch or a keynote making it difficult to sell. Ask others who may have exhibited or attended before you buy a booth.

Mini Ask-HN: What's the coolest piece of swag/kitsch that you've ever gotten from a booth (or a company in general)?

Coffee mug. Man, I need to go to better trade shows.

Oh wait - I once had my photo taken at a trade booth with a mermaid. But it wasn't a real mermaid, so that probably doesn't count.

1) Hire Ceren Ercen

Well, last I heard from her (which was earlier today), she's still looking for a job, but she's more looking for a sysadmin position than a booth babe gig.