It's been a common trope that many product focused founders have a somewhat dismissive approach to marketing. The mindset can be very "if you build something people love, the rest will work itself out".
If you identify with this characterization, or see it in a founder you know, here is a cautionary tale.
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Let's say that you build something people love, and for a little while it works. Early users show up, word spreads, and especially when you're riding on a hot narrative, things go pretty well. The product is good, the market is finding it, and things are working. You are not worried about marketing.
Phase One: The Tailwind.
You're growing, and you attribute it to the product. Maybe you're right. But you're also riding timing, novelty, or a wave that has nothing to do with you. Your marketing team, if you have one, is "getting the word out", launching products where your audience will see them, and hoping that's enough.
Phase Two: The Plateau.
Growth slows and you assume it's a product problem. So you build more features, ship faster, talk to users. You do everything except ask the harder question: do we actually know how we win? Because in the end, this is what marketing is - it's doing the work of figuring out how you win. Everything else is tactics.
Phase Three: Doubling Down on Tactics.
Maybe you push harder on outbound and content, try to ship faster, or in general do more of what you're already doing. Maybe you try to bring in a senior hire whose job is to "formalize" a strategy that was never really developed. None of this goes especially well.
Phase Four: The Reckoning.
You eventually realize that neglecting marketing is just neglecting figuring out how to make your business work in the long term, when the narrative dies and the competition shows up (which it will if your business makes any sense.) Hopefully you still have time to change your ways.
Positioning and messaging are the foundation the rest of your company is built on: if you haven't spent time figuring out what you are, who you are for, and how you make their life easier -- and you don't revisit this question on a semi regular basis -- worse products that are clearer about what they are will win customers that should have been yours.
The actual work of marketing is not promotion, it's figuring out how you win your market. Dismissing the importance of winning your market is, in every case, eventually lethal.