Running a pay-per-click (PPC) advertising campaign is a process. You first have to choose your keywords, and then bid on them, and then set up your ads and targeting settings. But it doesn't end there.

In fact, the bulk of the process comes down to monitoring results. Specifically, you need to dedicate plenty of time to tracking some key PPC metrics that will help you understand how to optimize your marketing. But how exactly does PPC tracking work, and which metrics should you keep up with?