Here's how pages work...
When someone "likes" your page, from there on they see all of your updates in their news feed, as if they were a friend of yours. You use this to market directly to them.
The initial "like" also shows to all of their friends in their news feeds, so if your page has an interesting enough name, they check it out, then possibly "like" it too, which their friends see, and so on...
Facebook is basically a walled garden for idiots who don't know better, marketers are pointing people there because that's where they hang.
Does make you wonder what happens if their FB account gets deleted for a ToS violation...