Better yet: find 10 people to write you a check.
If you're building something that your prospects want and your demo is so compelling, then smart people will crawl over each other to get their deposit in first. I've even had propects beg me to leave my laptop after a demo so they could play with it while I built it out.
10 people saying they'll buy it is a good start, but a deposit check separates the talkers from the doers.
Sometime I think investors should require 10 deposits prior to pitching. Imagine what a difference that would make.