If you study your target audience properly and with the right tools to analyze data, you can market narrow and deep. Sales should be #1 priority, I agree, so you can continue to collect feedback and make product iterations but saying marketing is broad and shallow is an incorrect statement. Digital marketing tools have evolved in the past few years and it's a lot easier to measure success on specific tactics. I think the old school mentality of marketing is "spray and prey" and if that is what one's thinking of marketing is, then they are not doing marketing correctly. The job of the marketer is to make the life of the sales person much easier so that the conversations they are having are meaningful and have greater chance for conversion.