I think they're all necessary. Product + grinding - building it and nobody comes, will get there eventually. Easier to learn to sell than to make a good produ

I think they're all necessary. Product + grinding - building it and nobody comes, will get there eventually. Easier to learn to sell than to make a good product. Sales + grinding - selling a turd, hopefully will get there. Harder to learn how to make a good product than sell. Product + sales - flame out early