Couldn't the whole internet be generalized as "file hosting with a bunch of links"? A "file host" is a company whose primary purpose is for you to upload a file and give the link to someone else; they're a middleman that exists only because a more convenient/direct means of distribution to the intended network isn't available. This does not make the company nearly loud enough to establish its own identity/user base.
Facebook has always been its own repository of people intelligence. It was never just an "upload your photos here". Such platforms, like Photobucket or Imgur, sometimes prosper for a while, until the communication channels that reach the intended audience directly offer something easier. (imgur is going down now as reddit introduced its own image host last year)
(Not that I use it.)
Realise that the flipside of such services is their real customers -- the adverts side. For online advertising, the two largest agencies claim over 60% of the market, and are named "Google" and "Facebook".
Everyone else is an also-ran. Which for any ads purchaser means "a lot more work for a lot less reach".