Potential to reach millions of people is made possible through Facebook. You can market your product through Facebook pages.
A page can have unlimited number of fans. When you start building your fan page, invite all your friends to be part of it.
Once they add themselves to you fans list, this activity will be visible to their friends through the news feed. The main difference between Facebook pages and Facebook profiles is that the former is visible via Internet search engines.
Once a member becomes a fan of your page, he/she can receive messages from your pages.
Use the share option to share your page with other members; this helps in bringing more people to your page.
Facebook has a flexible privacy model; you can share your page with only those you know or make it available on the Internet search engines.