Small evening calculation fun:
Having the wallet open for staking 24/7, which means having the computer always on drawing power, has so far given me a 0,016% return per 24 hours.
This amounts to 1,06% per year with interest of interest, less than half of normal inflation, a.k.a losing money.
So if my gains are representative this means that staking ETHD = a fool's game.
Staking is depends on the amount of coin you have on your wallet more coin = more returns.
I just double checked my last two days of staking. I am averaging right at my 10% yearly yield. Remember it's 10% a year. If you have 1000 coins, it is only 100 coins a year. That would only be about 0.27xxxx coins a day.
Edit. That also depends on how much you own because of weight. That is why they said about 10%.