that doesn't make sense, you have 24 hours to zap and thousands of posts/comments, how does that encourage random zaps?
You are saying it: you have 24hrs, hence, a day. That implies daily commitment. Just one day off and it's all gone. Expecting a user to not to miss a single day to keep score, as another user posted above, ends up causing anxiety. You have to devote time, and even more, mental energy, to consciously zap something you consider worthy. Most probably, you wont have that time and energy strictly every single day, so to not to lose score and rewards, you just enter quickly, zap blindly, and done.