You should consider which content marketing metrics are relevant. Not all metrics should be KPIs but some should be.
Content, capturing how much content did we produce.
Earned impressions, the amount of traffic generated from sharing
Social engagement, the rate at which people share
Conversion rate or Conversions, the rate at which people convert or number of people converting
Attention, how much attention consumers give our content
People, how many real people are seeing my content.
Content Benchmarks can be a useful starting point to consider, as they can ensure that your performance is at or better than your peers.
Quality metrics are useful KPIs as they ensure that your content is having an impact. However reach is also important to establish that you are having a big enough impact on the market.
Nudge has a platform the captures the most important KPIs for content marketers and shares them in one easy to use platform.