interestingly, a lot of enterprise Saas software is "sold before its built", by which i dont mean its complete vaporware, but its a very common practice to build a shitty first product, sell sell sell, and only after the first 10-20 customers are on board, do these companies start to spend more on engineering etc. Even after that, in order to sustain the machinery of building product, you need to keep selling. I think both are important, but in the technical world we tend to seriously underestimate how important sales it. At the end of the day, you can have the best alogrithms, the most elegant code and the sexiest UI, but if you dont have someone taking it to customers, and bringing their feedback back, all you have is a beautiful product without a business.