What is the best path for someone to break into Product Marketing for someone who is not fresh out of college?
There are two things I think you can do to help you here. One is stupidly easy, one is harder.
Let’s start with the hard one first: You might need to readjust your compensation or seniority expectations to get the role you want. You clearly have great experience and training, and I don’t think you should discount yourself, but sometimes moving into a new discipline might mean taking a “step back” in terms of what you’ll be paid and what your title will be. It sounds like you’re open to that given that you’re applying to entry and mid-level roles. But, if you’re going in with compensation expectations that are much higher than the role is scoped for, it’s likely you won’t get the role.
Now to the easy part: Once you decide you're willing to make the adjustments necessary to move into the role, communicate that in a cover letter or intro email! As a hiring manager I sometimes hesitate to interview more senior candidates for a role that I think might be too junior for them because I don’t want to end up in a position where a team member has outgrown their role in 9 months. But if a candidate communicates why they're making this move and why they want the role, I feel much more confident considering them, even if I see them as more senior than what I was looking for. My suggestion is to start with a cover letter. No one writes cover letters anymore. Or, if they do, they are completely impersonal and generic, touting the skills the candidate has without connecting to the job description whatsoever. It’s a shame because a cover letter is the best way for you to get out in front of any assumptions someone might make it looking at your resume. You can explain why you’re interested in the role, that you are willing to make a career shift because you’d like to get into product marketing, and what about the job stood out to you so much.
A few more tips: If you can, take on a few projects in your current role to help flex the PMM skillset and include that in your resume and in your cover letter. If you have friends who are product marketers, ask them about their roles and see if they know anyone that’s hiring that they can introduce you to. I don’t think you have to have an intro to get in a job, but I definitely make sure to talk to candidates that come highly recommended by people I respect, even if their background is a bit different than what I was originally looking for.
Good luck!