Whats the incentive for these sites? How do they stay operational?
> How do they stay operational?
By not growing too large (so costs don't explode) and the owner not minding to pay a bit to run it. Which usually means that they don't stay operational long-term-ish, or introduce stricter and stricter limits.
Image hosting sites are something where one could observe this very well over the years: an image hosting site launches and is fast and simple, operator offers generous service for free. Lots of people start using it. Bandwidth costs explode. Site adds advertising, cuts down on hotlinking, strictly limits free tiers ... to make some money back. Users get annoyed. Among them is a techy who thinks: "I can pay for a server or two, I'll launch a better image hosting site, without all the ads!". Such repeats the cycle of life (of image hosting sites)
Scale really hurts here - many people can easily run a service that doesn't have too many users (or many users that don't create much load) for years, but scale quickly pushes it out the side-hobby-thing budget.
Intelligence gathering operation?