How do you evaluate the impact of product marketing campaigns on customer adoption and retention rates? What metrics do you use to measure this impact?

Product marketing is an accelerant function. If you drive a change in the behaviours like additional programs, marketing, activation work, measure the uplift of either.

Even if it's a new product, there should be a forecast of baseline perspective of activities, or what is expected or hoped to accomplish. If there isn't, that should be the first step to assess before moving into additional activities. Assess what is needed, what the baseline is and then you can drive activation programs that are pointed at some point in the retention metrics or adoption metric funnel to change behavior that you can try to track.

For example, after your assessment you have an X customer reach out to number with a Y conversion rate, you can implement activities to try and affect change in either of those numbers. If you hit those numbers, you can try and claim credit for them based on your activities.

It's sometimes an art in stakeholder management to ensure the credit will also come to the Product Marketing team as an enablement function, but at least you have clear understanding of what was going to happen without Product Marketing support, and the additional activities can be credited in the right way. Understanding the business and the core metrics will be what drives the ability for the Product Marketing team to drive change, and if there isn't a core understanding of that, it will be a hard case to make.