Why does a view count show a negative number or zero?

Negative numbers on Viewstats usually show up when a channel changes a video to unlisted, private, or deletes it altogether.

YouTube's total view count only counts views on public videos, so changes to video visibility affect the overall count. Sometimes, negative numbers can happen because YouTube checks and corrects view counts, which it does from time to time to fix errors or update its systems. Also, you might see days with zero views when it takes longer than usual for a channel's total view count to update.