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The 3 Most Powerful Words in Sales

Just say it: "I don't know."

Too hard? It's worth practicing, especially if you work in sales, according to new research from the Boston University School of Management.

Barbara Bickart, Maureen Morrin, and S. Ratneshwar, all of the Boston University School of Management, conducted three tests designed to measure how trustworthy salespeople appeared, and how likely consumers were to buy from them. They found that for salespeople there is no downside to answering, "I don't know" when a customer or prospect asks a question that stumps them. And for salespeople who work on a commission basis, saying "I don't know" may actually seal the deal.

Expecting the Worst of Commission-Based Salespeople

In the first survey, 37 people read a script describing a situation in which a new employee is asking for information from a financial advisor associated with the company that sponsored their new 401(k). In that script, the employee asks the financial advisor if signing up for the 401(k) will impact their ability to contribute to an IRA. The financial advisor does not know the answer.

  • If the salesperson was on commission, 75% of the respondents expected the salesperson to blather on, trying to hide the fact that he or she did not know the answer.
  • If the salesperson had no financial incentive to sign up the employee, only 38% expected the salesperson to obfuscate.
"I Don't Know" Inspires Trust
In the second survey, 225 respondents were provided with one of three possible responses on the part of the financial advisor: A straightforward "I don't know," an unrelated answer, and the correct answer.
  • If the salesperson was on commission, admitting ignorance convinced people to buy. The survey respondents were more likely to say they would buy if they get an "I don't know" answer than if the salesperson beats around the bush.
  • If the salesperson was not on commission, it didn't matter what he said. If the salesperson was not on commission, the respondents were equally likely to buy no matter which answer the salesperson gave.
Beating Around the Bush, Bluster: A Deal Killer

The scenario was the same in the third test. But the 134 survey respondents were asked to give their thoughts about the salesperson. Beating around the bush turned out to be a deal killer for salespeople working on commission. The survey respondents described the salesperson as untrustworthy and said they were less likely to buy as a result.

The take away?

  • It's better to admit ignorance than to try to bluster your way through, especially if the customer or client knows you're working on commission.
  • Admitting ignorance makes you seem more trustworthy and credible in the eyes of the customer, not less. The professors speculate that what a salesperson loses in credibility from not knowing an answer he or she makes up for in trustworthiness from admitting their ignorance. In other words, they write, "dumb but honest" beats "clever but devious."
How do you react when someone can't or won't answer a straightforward question? And how comfortable are you saying "I don't know"? And do you think saying "I don't know" will help you with clients--or your boss?


Photo courtesy flickr user Belly Acres
Kimberly Weisul is a freelance writer and editor. Follow her at
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