it is actually not worth nothing, its just to small to show
but sometimes if mostly your vote shows as 0.00 it is actually 0.0005 or something
So all those votes that you think are nothing are fractions of a penny

And when you move over 500SP you can split up your vote so instead of voting 10 times 4,5 cents per day you can give 20 times 2,25 or 40 times 1,25 etc
that is why you get those percentages next to a vote sometimes