I used this service and received a 4% discount on purchasing power. I bought a contract for SHA256. I used OkPay for funding and then bought bitcoins for payment. Before making the purchase, I calculated the profitability and only then paid. The minimum amount for withdrawal from the project is 0.001 BTC, but it's better to accumulate more, as the service charges a fixed fee, and with small amounts, you can lose a significant portion. Overall, the project's profitability is about 170% per year. Although the amounts are not very large, the stable income is pleasing.
