How can I get started in setting up Product Marketing w/in my organization?

You'll earn buy-in by identifying the hole in your company that product marketing will fill. Do you currently have strategies for how to increase user adoption of features? Do you have a team dedicated to ideating features or offers that can serve both top-of-funnel growth and brand loyalty? Do you have any understanding if a feature could have had more adoption if different language or timing was deployed? If the answer is no to any of those questions, then your organization needs a product marketing function.

As far as metrics, it depends on the project but I find I'm most often looking to adoption and retention—did users adopt the new feature and did it improve their experience so they stuck around. AB testing is also crucial to the product marketing function so you can continue to iterate and personalize the experience to each user dependent on their usage, age, location, interests, etc.

Owning a product launch would be a great to get started in setting up the role of product marketing and defining the responsibilities of that role. By bringing together different x-functional stakeholders across sales, product, customer success and the rest of the marketing towards a launch date would be a concrete way to show the value of PMM. If you don't have a new product to launch, you could also simply create a launch moment of a product that's already been in market to boost its performance. Perhaps it's not a brand new product, but there's something new worth announcing externally (or even just internally) that you could use to bring the teams together by giving the sales and customer success teams an opportunity to reconnect with existing customers or reach out to prospects.