What you are referring to is commonly known as cloud mining. The only ones profiting from cloud mining are the companies providing the hashrate. The only way to profitably mine is by physically setting up a mining operation yourself, with hardware you own, infrastructure you can use and cheap electricity.
I just need to clarify this, Nicehash isn't a cloudmining service.It is sorta mining Pool but like a broker, instead of using the collected hashrate to mine an algorithm, they are selling them to anyone who needs it.
Unlike cloudmining, the sold hashpower didn't came from them, it came from collective hashing power from small-time miners who are "selling" their hashrate which is legitimate but unfortunately, not profitable at the moment.
@saooesnamax Read my first reply (#3). I already explained to you why it isn't a good idea.
