Facebook follows are specifically for people with personal Facebook profiles that have the follow button enabled. You can't buy Facebook follows for a Facebook fan page. If you're unsure what kind of page you have, you can reach out to us through our contact form and we'll help you out.
Here's the official Facebook page to enable the "Follow" feature on your profile: https://www.facebook.com/about/follow
Facebook follows are extremely useful. Any time you post something to your profile, each of your followers are immediately notified about your latest post. This makes follows arguably more valuable than Facebook likes, as when somebody has "liked" your page, they don't necessarily always see the content you post.