Typically a Product Marketing function will start with one generalist, followed by another generalist, followed by... ? When do you start to specialize PMM roles within your team? Which type of a specialist roles make the most sense to start with?

Great question. I don't actually know if it has to start with generalists and lead to specialists. I've been at some companies, like Chili Piper for example, that have 100% generalists who own specific product lines. 

I definitely agree that at least the first PMM should be a generalist. But at Klue for example, I'm adding two specialists as my first two hires just because they are internal team members who have been doing the roles of customer marketing and competitive enablement already. I had the opportunity to bring them over and I jumped on it. 

As a general rule of thumb I would say that generalists work well in smaller starups while in larger enterprises you start to see more specialization. 

In terms of what specialized roles to hire for first, I would say that it really depends on the needs of the business. Do they have a lot of stiff competition? Do they ship a lot of product? Is the sales team begging for collateral and customer stories? I mention those three things because that's what I would most likely look at first. 

That answer was all over the place, but hopefully it helps.