Engineers make the best marketers because, contrary to conventional wisdom, marketing is not a “soft science.” As a VC, I’ve done due diligence on hundreds of startups and am most impressed with those that run their marketing departments like engineering shops.

Taking an engineering approach to marketing simply means:

• Test everything
• Make decisions based on numbers
• Abide by the rule that the customer is always right

The same tenets I learned in the offline world with Proctor & Gamble and later in the hyperactive online world with NextCard (the third-largest online direct marketer at the time behind Yahoo and Microsoft), still apply today. Whether promoting paper towels, online credit cards or a hot new Web-based service, infusing marketing with analytical discipline will set your startup apart.

Let me give you an example: I sometimes hear marketing people say they chose one direct marketing campaign over another based on what they thought was better design. Decisions should be based on tests, not educated guesses because we usually guess wrong. While at NextCard, the largest issuer of online credit cards at the time, we created a somewhat cheesy ad very early on with a picture of a thermometer and the tag, “How low can you go?” We always thought we would replace it with something more sophisticated. But time after time, it was the ad that tested the best. So we kept it in our rotation of ads. That ad converted more customers than any other. And the customer is always right.

The best marketing people I’ve come across at startups also share a similar language with engineers. They talk about raw data, hard numbers and whether test results are “directionally” or “significantly” meaningful.  They have formulas and systems in place to give them up-to-the-minute information on what ad unit is converting customers at what rate and at what cost. (BTW, “directionally” meaningful simply means the sample size used was not statistically sufficient but informative, while “significantly” meaningful means the sample size was statistically adequate and dependable.)

When I worked at Proctor & Gamble, the majority of the people in brand marketing held engineering degrees. And it’s for good reason. A superior analytical, data-driven mindset leads to great marketing.