In your experience, what KPIs "must haves" for any product marketing role or team?

Depending on where the team focuses, Product Marketing can have a few different KPIs that are 'must-haves.' But the most common ones are:

• Product adoption -- definitely for features that PMM launches/brings to market, but if certain PMMs 'own' an area of the product then they should also co-own the overall adoption on an ongoing basis.
• Launch and/or campaign engagement -- you want to be able to speak to the success of your activities! The most common ones here are email opens/clicks, webpage and/or blog post visits, social mentions and sentiment, and (if possible) revenue metrics like leads, MQLs, pipeline/opportunities, or ARR.
• Win rates -- if you are investing in sales enablement, you want to see win rates go up over time. If you have a competitive intelligence dimension to that, with battlecards and competitive training, you should also track competitive win rates to see progress there. 

Must have KPIs will always vary from company to company based on size, industry, business model, etc (I have to add this disclaimer in). So, I'll break this out a bit by the stage of company I have been at.

At the earlier-stage B2B companies that I've been at, the core KPIs we tracked were:

Conversion Rate: The percentage of leads or website visitors that convert into paying customers. We as PMM would monitor this as it related to product or solution pages, to measure effectiveness of landing pages (that we were predominantly creating) and marketing campaigns where we created positioning and messaging.

Product Awareness and Reach: We focused on this metric, predominantly with any product launch or release - measuring metrics such as website traffic, social media engagement, and email open rates.

Product Adoption Rate: Again, we predominantly focused on this as it pertains to new product releases as a way to gage how and when and to what extent customers start using the product after its launch or release. However, it's also a large part of understanding the customer journey, which is next.

Customer Engagement Metrics: Tracking metrics like time spent on the product, feature usage, and interactions to indicate how engaged customers are with the product. This is a good signal towards retention and active users, etc.

These metrics are often shared with other teams like marketing counterparts around demand and growth and our product counterparts around adoption and engagement.