[throwawaaarrgh]

Sales/marketing don't even exist when a product is first being built, but you're getting paid... but your salary isn't R&D. The pace isn't calm. The stakes are high. The target can pivot violently.

Your salary is coming from the Business Plan's Capital Expenditure, as part of an initial round of investment needed to achieve the Business Goals. This is a marked difference from Operational Expenditure, which "Maintenance" is most often lumped under.

Whether your salary is CapEx or OpEx has a much larger impact on your ability to work freely and productively than what of these 3 (really 4) categories are.

[prepend]

I think a better way to think is as product development. Sales and marketing exist from the beginning even though nothing is being sold yet.