As a sales trainer I spend quite a bit of time talking to businesses about their sources of revenue. Frequently, I find myself discussing not only their training budget, but all of the line items that make up their Cost of Sales numbers. And more often than not, part of that cost is marketing. But as I look at their Cost of Sales, it often reminds me of my mom's riddle. I ask "Why do you spend this money on marketing?" And the single most common answer is "because our sales team doesn't work."