My understanding is it is due to the difficulty increasing but I'm skeptical because one would expect this to be across the board globally but around a month ago my Genesis mining contracts that was paying .0015 avg. daily for a few months dropped to .00075 avg for a few weeks now down to .0005 daily which is about a 1/3 of what it used to be however my mining contracts with Hashflare and elsewhere did not drop until recently and no where close to the level of Genesis.  I have a support ticket in asking why but of course like everywhere else, they are back logged and I'll likely wait a month to get a response which of course will also likely be generic and not answer my question.