Actually, I think it's per ticket with no reference to the time period.
If the ticket takes 1 month to vote, then it also happens to be per month but you can't know that.
It has 50% chance to vote within a month and must vote within 6 months ore expire.
This is a return of currently 2.34 percent. With continuous buying, this value works out to be return per month. With at least ~100 tickets you can expect to see this return each month. Fewer tickets will still average to this value each month over time, but you will see increased variation on a month-to-month basis.
is anybody smart enough to figure this out if the above statement is correct?
The statement
It has 50% chance to vote within a month is not quite true. Actually on
average each ticket will vote in
28 days. Read the official Decred thread for all the details but it is technical:
https://docs.decred.org/mining/proof-of-stake/ I found the ROI statement on
https://dcrstats.com/ seems pretty accurate.
Yes, and you need another full day for the stake to mature, and then another for a ticket purchase to mature again. So the whole cycle takes about 30 days.
Also, it is possible that the ticket votes from the beginning (after it matures) instead of 28 days, which means you can rebuy and start the cycle again even earlier.
So if I buy 100 tickets in day 1, I would expect at day 30 to have more than 50 voted as some of them will have voted very early and others would be bought in their place in the mean time.
But still I would not expect to have 100 voted on average every 30 days, so the return per month should be less that 2.34% because that return would imply that with X tickets holding (and rebuying) you get on average X votes per month
big UP when all return normal 
