I started by building my list via my current business email list. Since so many customers asked for a software, I informed them that I began building it. I created a simple signup landing page and told them they could get more information there.
I started building the list about 5 or 6 weeks before doing the preorders and I was able to build my list up to about 1,450 people. In addition to the mailing list, I also created a Facebook group which was about 175 people.
The purpose of the Facebook group is customer feedback and relations. I want to be able to have a very close and personal communication channel with my customers and potential customers.
I ran preorders for about 1 week sending emails nearly daily and posting a couple of times to the Facebook group. Over the course of a week, I was able to sell about $5,400 in preorders.