Let’s suppose I gave you a quiz and asked, “Which of the following is the most important skill for online marketing in 2011? Is it social media marketing? Search engine optimization? Pay-per-click advertising? Video optimization? Mobile marketing? Well, would you believe me if I said, “None of the above”? Yep. None of them. I regularly argue that digital marketing is a core skill. And it is. Each of these talents contributes to your success as a marketer and to your business results. But they’re not the whole enchilada. In fact, they’re probably the least important ingredients in the recipe.

So what is the most important skill? What makes successful marketers successful?

There are only two skills that matter to all marketers, online and off:

  1. Listening.
  2. The ability to learn.

OK, I realize these are two skills, not just the single most important skill. But bear with me for a moment. Each of these abilities complements the other. Someone who listens but can’t learn from it is nothing more than a vault for storing information, never to be cracked. And someone who can learn but never listens will never gain the necessary information to learn from. Each is critical for successful marketing campaigns and successful marketing careers.

A friend of mine—a guy—once worked for a cosmetics company. He claimed that he was a better marketer than many of the people–mainly women–who had worked there for years because he knew he didn’t know anything about cosmetics and was forced to listen more to his customers. His weakness—unfamiliarity with the product and the needs of the customer—forced him to be a better listener and to learn from what he heard in order to succeed in his role.

Which, of course, begs the question: “How can you listen to your customers online?” Well, that’s where your other skills come in. For instance, you can use tools and techniques like these to listen and learn from your customers:

  1. Social Media. Whether you use simple tools like Google Alerts or sophisticated social media monitoring suites, social is integral to learning what your customers think about your brand.
  2. Analytics. Tons of analytic tactics exist to find out what your customers are thinking. For instance, check out the top keywords that your customers use to find you and see what matters to them. Just remember, your analytics are only showing you the searches that resulted in a visit, not the ones that matter to your customer where you don’t even show up. The same is true for all the other data about your site, too.
  3. Surveys. Loads of excellent options exist for conducting customer surveys online, ranging from sophisticated tools, such as SurveyMonkey, UserVoice and Zoomerang, to simple-to-administer, but limited Google Forms. Additionally, tools like iPerception’s 4Q offer your customers the ability to let you know what they think about your Web site–and give you the ability to learn from it.
  4. Usability testing. Even simple tests, such as those offered by sites like UserTesting.com can provide you with tremendous insights into your customer’s behavior.

As you move forward with your marketing, you’ll almost certainly need different skills than you have today. Social media and search engines—as dominant as they are today—might not be with us forever. And even if you’re still doing search engine marketing or social media optimization, I doubt highly you’ll be doing exactly what you do now. But, no matter what choices you’re offered on a “most important skill” quiz years from now, listening to your customers and learning from what they say will always be the right answer.