by downvote do you mean flag? or just choosing not to vote at all?
Your idea is a cool one. As someone who spends 10-12 hours a week just for one hangout, I have a bias toward your approach. However, I will say that if someone announces that hillary clinton is going to prison---I will upvote that before I upvote my own comment ;)
I guess my point is...there ARE some sexy announcements worth paying a good bit for, and if everyone announces certain things in a flood of copycat posts it may not always be a bad thing (though most the time it likely will be).