I don't at this point. I think the magic number is having 480 steempower. At that point you are given a sliding scale to determine what percentage of a vote you wish to give.

At this point I can give a penny until I've voted about 50x in a day. It degrades my power at that point to less than a penny.

So if you're a whale with $1M worth of steempower, your full strength vote may be worth $20, they can scale it down to 10% and vote 500 times in a day, giving out $2 each time.