* Are persistant and laser-focused on getting deals to close.
* Can turn off every part of their brain that would prevent or delay them from asking for the sale.
* Have a nose for the org chart and for figuring out who needs to be sold to how.
* Can accurately gauge where they are in the sales process for any prospect, engagement, or eval --- this rarely has anything to do with technology and usually has everything to do with budgeting, MBO's, and getting bakeoffs started.
* Take meetings and make visits relentlessly.
* Appear confident, like the guy-in-the-rated-R-movie.
Most of this isn't helped by product knowledge, and some of it is actively hindered by in-depth knowledge (for instance, by creating doubts about whether now's the right time to ask to close a deal with someone considering or evaluating).
I always sound like I know exactly what I'm talking about, and often I don't, so don't hesitate to tell me I'm wrong; I'll learn from it. My sense of it is that it's very hard for a tech person to be a good salesperson. Not impossible, but not statistically favored.