Why do I have zero actions but lots of impressions?
I don't understand; what's the difference between an action and an impression?
Every time your ad is served, you gain another impression. That's data we receive automatically and pass along to you. It's how we know when a publisher should get paid, so it's a pretty important number.
An action, on the other hand, comes from action pixels: tiny pixels that you install on a page to get more specific data that you can use to calculate a more accurate ROI calculation. If you'd like to install an action beacon, read more here.