The common boast of salespeople is, “I may not know the answer, but I know where to get it.” It’s a great statement of credibility for young salespeople, and even seasoned veterans, when faced with an unusual technical challenge. It’s not a good answer to use as a crutch throughout a career. If there’s one thing better than knowing where to find the answer, it’s knowing the answer itself.

It’s the difference between simply being a likeable salesperson and a credible sales leader. Robert Cialdini, psychologist and author of “Influence: The Psychology of Persuasion,” notes that two factors must be present to gain the authority of credibility. These are trust and expertise.

His book is worth reading by all business leaders and has been translated into dozens of languages. The implication of his work on credibility is proof that sales leadership requires more than having a good personality and being likeable to customers. Sympathy is of course essential and a key element of trust, but it does not create full credibility until expertise is displayed.

In his book, he cites the example of physical therapy staff at a hospital who lamented the frustration that patients were not completing their post-visit exercises for successful rehabilitation. He noted that patients were familiar with the credentials of their doctors, but had little understanding of the backgrounds of their physical therapists. (Today, physical therapists are required to obtain a doctorate as a prerequisite to practice.)

Cialdini suggested that physical therapists make a subtle change in their environment by displaying their credentials prominently on the walls of their office. The results were dramatic and led to a 34% increase in patient compliance. Analogously, this implies that sellers who want to increase their credibility must demonstrate their authority which, unfortunately, will not come in the form of a diploma.

Unlike physical therapists, doctors, lawyers, accountants, traders and a host of other professional categories, salespeople are not certified for their business skills. Instead, the authority they earn is determined by the level of trust in their established expertise with their customer base. In other words, it means knowing your stuff.

There are basically two ways for salespeople to assert authority with customers. The first is obviously the knowledge of their products and their applications. The second is to provide expert business development advice that their buyers can rely on.

In the first case, it means diligent self-study. I’ve worked with too many salespeople, often manufacturers’ representatives, who know less about their products than the information listed in their company’s brochures. It is the sellers responsibility to read the brochures and diligently study their product specifications, options and applications. The salesperson waiting to be spoon-fed product knowledge is guaranteed to fall behind.

In the latter case, that is, providing sound business advice, the best salespeople are not just product experts, but students of their clients’ businesses. High-performing sellers understand how they can help their clients market and sell their services, create operational efficiencies, and generally become better contributors to their clients’ success.

Salespeople have often asked me why they need to know all the intricacies of their clients’ trades. Obviously, this counts when supplying products. More subtly, the benefit lies in their ability to become consultative contributors to customer success. In other words, top sales leaders provide advice on how to increase profitability for their customers, which often has nothing to do with the products the salesperson sells.

It’s one thing to know where to find the answers. It’s a whole other thing to build a library of knowledge that puts the answers at your fingertips. Become a better business student. The sooner you become a better student of business, the sooner you will become a teacher of it.

Rick Davis is the sales training manager for ABC Supply and the president of Building Leaders. You can buy his books or learn more about his online sales training platform at