Why is your BTC exchange rate so high?
WinMiner base currency is USD. That means that your balance (in USD) is guaranteed and protected from coins fluctuations. To do so, WinMiner exchanges coins mined into USD.
When a user wants to withdraw, we take the balance (in USD) and carry out the user withdrawal order, whether a PayPal transfer (in USD) or BTC or ETH (in which case we purchase the coins for the user and make the transfer).
When buying ETH or BTC using USD a fee is imposed by the exchange, usually in the form of an exchange rate.
Hope this clarifies.
BTW, at the request of our users we are working on adding a feature that will allow users to choose their own base currency - that way a user that wants to be exposed to the volatility of a certain coin and would want to withdraw in that coin could keep his balance in that coin and avoid exchange costs.
That's not even counting the fact that we have no visibility into how you calculate your rewards. We can see a rate that your application says it's mining at, but we have no idea if this is the actual rate we receive, or if it's an estimation (like NH's miner) with different results on the server side. Your daily bar chart doesn't do a lot here to give us any view into how we're performing at any given time. I'm not suggesting you're deliberately deceiving us, but the fact we cannot see what's going on makes it difficult to trust. At least NiceHash gives you a time-graph of profitability, and you can see where you land at any time during the day.
Profit data is provided online, with some delay (between 1 - 2 hrs), at a breakdown of 10 mins.
We are working on making the data update more frequently.