all the cloudmining companies mainly
1.genesis-mining
2.hashflare
3.oxbtc
these type companies may take only cryptocurrencies as primary payment or they put the usd payment as secondary option if you observe that as 1 th/s is around 200 usd if you buy btc worth 200 usd and stake them they would get around 250 usd or more in a year so why anyone will invest in cloud mining simply they take from us and they pay us and they only update the balance once a day which is fixed so that the companies can take an amount of mined revenue from our mining power.
and recently they even started the limited period of bitcoin mining contracts.
