EDIT: I started bot, not running right now, because I don't have enough bandwidth
I'm writing a bot that will scan all of the accounts on the Steem blockchain, and remind them to vote for witnesses, if they haven't. It will only remind accounts that have posted within the last 10 days, to make sure I'm not wasting bandwidth on dead accounts.
It will also search for people who are voting for dead witnesses, and remind them to stop voting for dead witnesses. If less dead witnesses are in the top 100, then actual block-producing witnesses will be able to get paid, instead of dead witnesses taking up space.
The reminders will be sent out as savings transfers, which will then be immediately cancelled. That way, it doesn't cost me any STEEM/SBD. It still costs me a small amount of bandwidth, which is why I'm only sending reminders to active non-voters.
I haven't started the bot, but I will soon. I estimate it will send out 50000 to 100000 reminders, in total.