Due to the sharp increase in mining fees in late 2017 and early 2018, we decided to start charging a mining fee of 0.001 BTC last November.
After receiving feedback from our users and in light of the recent drop in mining fees, we have reduced our mining fee by 90%, from a minimum of 0.001 BTC to a minimum of 0.0001 BTC. We have also implemented a ceiling so that if the average mining fee of the last 30 days exceeds 0.0001 BTC, the fee will be that amount instead.
Example: If mining fees increase and the 30 day average fee amount is 0.0002 BTC, the mining fee will be 0.0002 BTC.
We anticipate being able to implement Segwit by the end of 2018, which should ideally allow us to reduce our fees even further.