Clicks: Counted every time an affiliate link or marketing asset (ie. a banner) is clicked on, and a user/customer lands on your site.
Conversions: Counted when an affiliate has successfully driven a conversion (a sale)
Customers: Counted when an affiliate has successfully driven a customer (a sign up or a lead).
Note: If you need more information on the difference between a Conversion and a Customer, you can refer to our "Understanding customers vs. conversions" article.
The number of tracking events per plan vary. If you go over your plans allocated number of clicks, views, or conversions, these will be billed as an overage.