If yobit could guarantee the payment every day for at least 365 days straight that would be 72% annual interest which is way more than any banks offering right now, at least in my country most interest rates are around 23% max but they are banks, yet what other exchanges or cloud mining services which they own their own mining pools as well are offering is a very good deal IMO.
If they would somehow guarantee that you will be able to get your coins back any moment it would be nice.
Not talking about the 72% interest.
I deposit to poloniex then lend my bitcoins using their virtually risk free lending portal, I get good interest on all my bitcoin savings there.
I think the most important thing is "virtual".
Cause in reality you might soon find out it there is no such thing as "risk free".
And poloniex of all thing.... meh