When I began teaching sales, I never expected to one day give a student an "A" for bartering her way from a 25-cent pen to a 30-pound head of the Buddha. Or to a copy of a Nobel Prize-winning article autographed by its author that sold a few days later for $500 on eBay. 

The barter assignment is the first one I make in my "Entrepreneurial Selling" course at the University of Chicago's Booth School of Business. Students are required to barter a pen for something they believe is of greater value, and then to make one new trade a week for 10 weeks. They cannot barter with someone they know. They can barter for whatever they like, but it must be something they can then trade forward. After the trade is done, they consult eBay and Craigslist to determine the value of each item. 

The purpose of the assignment is simple: it forces students to stare rejection in the face and come away stronger. Is there a better metaphor for sales? For entrepreneurship?  A typical series of trades might go like this: 

Trade 1: $0.25 Chicago Booth pen for a $3 coffee mug (new)

Trade 2: $3 coffee mug for a $5 surge protector (used)

Trade 3: $5 surge protector for an $8 black hat (adjustable, new) 

Trade 4: $8 black hat for a $20 water filter (new, unopened)

Trade 5: $20 water filter for a $20 Swiffer (used, but with extra wipes)

Trade 6: $20 Swiffer for a $12 set of two Xbox games (promised $24 value, turned out to be $12)

Trade 7: $12 set of two Xbox games for a $20 PS3 game (used)

Trade 8: $20 PS3 game for a $30 set of books (The Art of War, The Lean Start-up, and The Sentimentalist)

Trade 9: $30 set of books for a $50 portable DVD player (with case and two power cords)

Trade 10: $50 portable DVD player for a $180 iPhone 4 (used)

If you're counting, that's nearly a 72,000 percent increase in value.

I love this assignment. My students? Not so much. But the lessons come rapid fire, whether they want them to or not. Here are three of them: 

Lesson 1: An 'ask' is a powerful thing. It is human nature to avoid uncomfortable situations. Unfortunately, the selling process is chock full of them: making an approach, starting a conversation, qualifying, proposing, asking for things. Throughout my course, students realize that they--like most people--constantly, unconsciously, avoid asking directly for what they want. They dance. They are friendly. They are easy to deal with. They talk about the wonderful features of the pen. Those are all good instincts. But they don't put food on the table. In any situation, you must be prepared to make an ask. "Jim, would you be willing to trade me that coffee mug for this pen?" Pause. "Susan, how about we trade this vacuum cleaner for that iPhone?" Pause. The thing that stops you from making a direct ask of someone is fear. And fear is normal. But the worst outcome is that the person says "No." When that happens, thank them and move on.

Lesson 2: Tell a story. If you dive too early into your ask, you may put people off and be rejected. Engage them in a story first, and they will be much more likely to connect with you. Stories show people the context in which you do something--the why and how of what you do. That makes them more receptive to helping you make a deal. For this exercise, the students might tell stories about their journeys with the pen, their failures in trading so far, or even their funny rejections.

Lesson 3: Create value. The barter assignment also teaches students to broaden their understanding of what constitutes value. They have to see value where others may not. The "value" they create with a pen (or a statue or a vacuum) depends on the context they create: the story they tell about its history; its utility; the cachet that comes from owning it; the services provided with it, and many other characteristics. Why call a pen a pen, when this supremely useful tool creates so many types of value? Just ask Shakespeare. 

As one student wrote to me: "The day before this assignment was due, I walked out of a building and saw a similar-looking pen to the one you gave us on the first day of class. I couldn't help but think, 'Who would be so foolish as to leave something so valuable on the ground?'"