I saw pretty easily how Instagram could be worth a billion to FB, who has a social network and wants to expand their user base / stop competition from rising.

I saw pretty easily how Instagram could be worth a billion to FB, who has a social network and wants to expand their user base / stop competition from rising. I don't understand how these shares that pay no dividend and give no voting power are worth $24 each. They are basically "SnapChat Fun Bucks." Anyone buying it just hoping another person down the line will pay more for it. On top of that, we know there's a large number of people holding it (employees) that are going to start selling their shares over the next year. I just don't get how this has any value at all.