-
Sales win rate, more specifically competitive win rate
Make sure that you're reps are populating a "primary competitor" field in your CRM so you can track this effectively. You'll then be able to track win rates over time and show how your efforts to enable your team with competitive content is driving you win rates up. -
Influenced deals
Is your PMM team responsible for things like customer references, creating custom content (ie. decks or leave behinds), or generally brought in to help on strategic deals? If so, add a special field to Opportunities in your CRM so you can mark when you've "influenced" a deal. This will give you an additional way to show how your work, especially ad-hoc requests, are influencing revenue. -
Sales confidence
Distribute a quarterly survey to the sales team asking them to rank their confidence in the ways you support them. Some ideas are: 1) competitive enablement 2) collateral and 3) product positioning and messaging. -
New product revenue
If you're launching a new product or service offering, track revenue during the first 30-60-90 days since this is largely a result of your GTM launch.
A bonus tip that's less of a measurable metric: any time someone praises your team, like a sales rep, department leader, customer, etc. grab a screenshot of that shit and save it all somewhere. It can never hurt to have social proof that your team is killing it.