Hello all.

In the course of the last month I purchased five small BTC contracts in minergate and two in XMR.  After observing inconsistencies in my profits I started investigating a bit deeper and I came to the conclusion that minergate's practices are at least suspicious.

Here is a table of my contracts

On 11 Nov 2017  I bought 275 GH/s I paid 0.00588500  BTC with average profit   0.00001617 BTC/day  or 5.88 satoshi/GH
On 14 Nov 2017  I bought   60 GH/s I paid 0.00134760  BTC with average profit   0.00000369 BTC/day  or 6.15 satoshi/GH
On 18 Nov 2017  I bought   60 GH/s I paid 0.00110520  BTC with average profit   0.00000302 BTC/day  or 5.03 satoshi/GH
On 26 Nov 2017  I bought 140 GH/s I paid 0.00233660  BTC with average profit   0.00000642 BTC/day  or 4.59 satoshi/GH
On   2 Dec 2017  I bought   80 GH/s I paid 0.00117360  BTC with average profit   0.00000322 BTC/day  or 4.03 satoshi/GH

As we can see from the above table the profit per GH is pretty inconsistent and can differ by up to 53%.  I find it hard to believe that this is due to factors like luck of the pool.  Minergate claims that collaborates with hashing24 and that they offer real mining contracts.

The suspicious part here is that for all five contracts the amount of BTC paid divided by the average BTC gained per day is the same and exactly 365 days.  This means that the profit you get is fixed by the amount of BTC you paid and not by the amount of hashing power you purchased.  Assuming constant difficulty, ROI is fixed to one year at the time of purchase.

From minergate's part there is no information to be found regarding these practices.  I have raised a support ticket asking for clarifications, although from past experience with them I have little hope I will get any answer at all.

Let's also mention that my two XMR contracts follow exactly the same pattern, ROI in one year assuming no change in difficulty.

Conclusions     In minergate you don't get paid proportionally to the hashing power you buy, but rather your profit if fixed by the amount of BTC spent.  These practices are at least suspicious and instead of mining it feels like you lend money to them.  Since the difficulty of BTC changes it remains to be seen whether you ever get your investment back.

Open questions   Since my contracts are relatively new I would like to know what happens when the mining difficulty changes.  Any of you with older contracts can share your experience and tell us how profit changes with time? What is your ROI time?  By ROI time I mean the time you need to get your satoshi back, not the time to get your dollars back.  This is a common misconception I encountered in minergate chat, which misconception is supported by the fact that minergate claims ROI in 120 days and they only save your daily profit in dollars instead of BTC.