I'm newbie here,Are there any legit bitcoin mining company or basically most of them are just scam.
Some of them
are real, but before you are starting to use one I suggest you do your research about that site first. Most of the new people are too naive to do that and think they can be rich in no-time with it. And before they know it all of their savings are gone.
I agree. Everyone would need to do some research and be realistic about it. These days if you get 1TH/s don't expect a miracle. Neither would I recommend ETH or Monero mining on GM. The ROI is not good and the prices too high for their contracts.
If you wouldn't use an Antminer S7 with 4.77TH/s these days don't complain if your 2TH/s gets less and less profitable. It's a the same game as per hardware mining yourself. At some stage you need to upgrade if you want to remain profitable.
4.77 is too less to start because we know bitcoin difficulty is increase every hours and if we only use s7, then we can not expecting make profit in a month. beside that we need to calculate about electricity fee (this is the most big problem for miner). i've done for mining in the past and i think i don't recommended for people to mining bitcoin if they don't have big hashrate but i suggest to mining altcoin because the possibility to make profit is still wide open but its depend on the coins we are mining.