Ask 25 affiliate managers to name the most important affiliate marketing KPIs, and you get 17 different answers – at least! And they all have excellent arguments to back up their choices.

The reason for such high variance is that affiliate marketing is embedded in an overall digital marketing strategy and the KPIs need to align.

What does that mean? As an affiliate manager, you'll track many metrics as indicators for the growth of an affiliate program. Not all are indicative of the progress towards reaching marketing goals. So, define what is affiliate marketing's role in your marketing mix.

If the main purpose is to drive traffic, you'll focus on traffic-related metrics. Affiliate marketing that is supposed to increase sales should be evaluated by revenue-related metrics. These are your key performance indicators or KPIs.