How should product split feature adoption KPIs with the product marketing team?

It really depends on what type of business it is. For instance, a product feature or product should be so frictionless that it allows users to onboard (adopt) easily once they are in the experience. Product marketing is responsible for bringing users to that experience. So it is almost eyeballs vs. activation. In reality these metrics should be shared, and over time broken up where the tech is meant to solve for the customer's need.

It's worth ensuring you collaborate closely with your PMM to ensure you know who is responsible for what along all touchpoints. In general, top of the funnel channels owned by marketing should be owned by their team (social, paid, blog, email, etc). Everything else should be owned by the product/design/engineering team (with the exception when marketing owns the development of those product ie. lead gen with "no code" tools). The touchpoints where marketing hands customers over to the product experience should have the right metrics tracked to understand A) the quantity and quality of users and B) how they are experiencing the product. Regardless of who owns what, product should be sure they have the full customer experience tracked (because if it's not tracked, product will be on the hook!)

I'd suggest dont split the KPIs. Here is why

Product Management and Product Marketing are two different ways to accomplish the same outcomes. The difference is one is in product and the other is outside of product but both the experiences are touching the same customer and driving the same north star outcomes. 

But in some cases that may not be possible either because of the org structure or just how your company functions. If that is the case I would suggest to map out both the in product and out of product journeys on a unified customer timeline and then go through identifying KPIs, dependent KPIs and counter metrics. Whether the org structure permits or not, Product Management and Product Marketing is dependent on each other, what one does will impact the other one and vice versa.

This has been a hot topic on my team recently. I think the default answer for many is that PMs own all of the metrics around a feature launch, including adoption. However, I believe that Product Marketing and Product need to be incredibly close partners on adoption KPIs, with each partner measuring the levers that they have control over to understand where they can drive the most impact.

Once a feature is launched, the PM can listen to customer feedback and look at usage data to understand what is and isn't working and begin to incorporate some of those changes (albeit weighed against everything else in their backlog).

PMM, however, does not need to get engineering involved to experiment and iterate with adoption. For example, maybe they are seeing better adoption rates with customers that click through their Pendo guide before trying the new feature. Can they perhaps begin to segment the overall customer base and make guides that are targeted by vertical or use case and retarget the customers that skipped it the first time?

While team members from product and product marketing should collaborate closely on every phase of a launch KPIs from awareness through adoption, each team should lean into the strengths of where they can drive that adoption to really move the needle.