How you got your first 100 paying users?

pay them to pay u

Create an amazing free trial and give them some real value. They will always want more at the end of it.

Find 100 people who want what you're offering enough to pay you. Find a need, then offer a compelling solution.

Appsumo's got this website full of stories of how people got their first 3 customers. I think that first step is much harder than going from 3 to a 100.

http://www.howigotmyfirst3customers.com/

some success stories about getting first users - http://vusal.me/handbook/