Who is actually buying alt-coin hash?
There are three different ways to get coins, which is the best one changes daily.
1) buy them
2) buy mining hardware and mine them
3) buy hash and mine them
I will give you an example:
You think xmr is going to shoot up and you want to invest $10,000, are you going to
1) buy xmr
2) buy gpu´s and cpu´s and start building rigs
3) buy hash and start mining right now without hassle and power costs
Best way is to run your own private pool where you point that hash, hardest part nowadays is to get large cheap fixed order through, need to do some bot fighting.
edit: forgot to say, some people buy hash from nicehash and sell it on some other renting sites. Buy low, sell high=profit ))