I would not recommend Genesis Mining. I have 30Mhs of ETH mining with them and since my contract started 4 weeks ago I've already had to write multiple support tickets for missing payments. Each time I write them they give a different excuse for why they missed a payment for over .06 ETH and a $5 ref. commission. On top of all that my daily profit has decreased by 30% in that short amount of time.
I have had a similar yet different experience. I have 60Mhs of ETH and i have seen my rate drop but that is due to more people mining ETH. That is clearly expected with mining. Even if you purchased your own rig it would be mining less now that it was a few weeks ago. As for daily profit.....my has gone down as well but that is due to the price of ETH dropping too, is your 30% figure based on ETH or $$$ amount ...with the upswing today my profit is going up....I am pretty sure this is the risk/benefit to mining.