I've been working in software for a long time, and other than inexpensive / simple consumer software or inexpensive departmental IT software, I've never seen pr

I've been working in software for a long time, and other than inexpensive / simple consumer software or inexpensive departmental IT software, I've never seen products that sell themselves. Marketing at the very least is required, and for anything remotely complex, that's what sales is for. Sales does something nearly as important as building the software: they map a customer's opportunity or problem to a technical solution, and ensuring they're successful with it. Sales (and marketing, which is arguably the evolution of sales at scale) are the field forces in discovering and exploiting product/market fit. No feature list survives first contact with the customer. Sales creates customers, and thus create markets. You might have a great piece of software but if no one can explain it, no one will understand it, and it won't sell. This is the difference between software that costs $1k and $100k+. The price is reflective of the value it can provide and who is buying it. Now in very small companies, the engineers are also marketers and salespeople. But beyond (say) 50 people, the divide between engineering and customers gets wider unless you have very good communication between sales, marketing, product, and engineering. There's too much work for everyone to focus on everything.