Campaign performance in OptiMonk is reported based on if your campaigns have reached their goal, which you can now define in Editor by changing the 'Campaign goal reached' toggle when the user clicks on a button. The campaign goal for popup campaigns in most cases is email or sms subscription, which this setting is very straightforward with.
However, for other use cases (product recommendations, Dynamic Content, announcement campaigns), your campaign goal might be different and hence, you might want to measure your campaign performance differently. For example: