Tweet That’s the word from our own Brian Carroll, who made that proclamation in an interview at the MarketingSherpa Email Summit this week. Paradoxically, this is why it’s critical to be strategic. He explains there’s a lot of ways to acquire leads, but there’s no determining which ones work best without testing. But what compounds the situation is that marketers don’t have the time or resources to test every potential tactic. This is why Carroll advises looking at marketing like a portfolio manager looks at a mutual fund. They analyze the financial marketplace.