Megaupload was selling access to content, not ability to store data. The users who downloaded data were the ones that had to pay. Only way this type of service is profitable is when it has "stuff" that is wanted by masses of people. And since Megaupload didn't produce/resell anything, illegal content is the only other option.

Also, during the time megauplaod existed, there always were upload providers. Megaupload came quite late into the game.

> Megaupload was selling access to content

Google and Co is also selling... your content whenever is legal or not

Can you go to google.com/somethingyouwantforfree and just download it?

No, no you can't.

There is a wildly obvious difference here and unless you're being deliberately dishonest, you'd have to be a complete idiot not to see it.

Dropbox public folders?

If they're of any appreciable size, they're paid for by the people hosting, not downloading. You do know this, right?

Of course.... but who pays (and for what, exactly) is somewhat immaterial. You're able to post public links to files and get (effectively) unlimited downloads via Dropbox too. It was a counter-example to your Google.com/yourdesiredfile

Who pays (and why) is hardly immaterial when it has a defining effect on how the site is actually used. There's a good reason as to why Google and Dropbox can easily claim legitimacy while Mega has to struggle.