how much TH/s you need to invest to make profit?
Anyone care to explain.
Was looking in hashflare cloudmining.
I think that magneto's answer is the most accurate.
The more you invest the more likely you are going to lose. Let's face it, unless you are able to refer some user into whatever service you are using you are likely not to gain much of a profit from investing in cloud mining.
Don't buy the crap that youtubers are trying to feed you. They only invest in cloud mining because they know they can get other people into it, and they earn a percentage. So really, it's more of a pyramid scheme than actual bitcoin mining.