Several years ago, fourteen teams of college students in the Stanford Technology Ventures Program were tasked with growing $5 in seed money in 2 hours.

One of the teams set up a bicycle tire refilling station on campus. The team offered to check students’ tire pressure for free. If the pressure was low, they charged $1 to add air using a portable hand pump. A few students stopped to get their tires checked and some forked over $1 to get air added to their tires.

After an hour, the team tried a different approach. Rather than charge $1 to top off the air in the tires, they put out a jar asking for donations.

Then a funny thing happened: People who stopped by started donating money. Lots of money. Way more than $1 per person, on average. And many of the students donated money whether the tire check showed that they needed air or not.

It doesn’t make sense, does it? Why would people pay money for a free service? It’s because of the principle of reciprocity. Reciprocity in social psychology refers to responding to a positive action with another positive action – rewarding kind actions. Or to state it another way, we feel obligated to repay favors and gifts. Once the bicycle owners received the tire pressure check, they felt indebted to the team that provided the free service.

In Influence: The Psychology of Persuasion, Robert Cialdini writes that we are hard-wired to respond positively to a gift, even if we didn’t ask for it, or even want it. We automatically feel indebted to the giver, regardless.

Reciprocity is not a new concept. Nor is it unique to college campuses. All human societies subscribe to the principle that we are obligated to repay favors and gifts. If a friend offers to drive you to work because your car is in the shop, then chances are that you will likely feel an obligation to return the favor.

Marketers have used the principle of reciprocity for decades. The children’s charity, March of Dimes, has sent out direct mail pieces for years with a dime showing through a transparent window in the envelope. Why? Because it works! Likewise, you’ve no doubt received mailers from other charities containing free calendars or personalized address labels. It doesn’t matter that you never asked them to send you a calendar. Some people feel obligated to return the favor by sending a check to the charity.

Does every person send a check to March of Dimes? No, of course not.

Your sense of obligation to return a favor doesn’t always outweigh other considerations. But sometimes it does. Often enough, in fact, to provide a favorable return on the charity’s investment. That little dime mailer returns about $20 million annually to the March of Dimes. It’s a great illustration of the fact that reciprocity often results in exchanges of completely unequal value.

The principle of reciprocity is at work when you host PDH events for engineers. A PDH event is a webinar or lunch & learn where you present an educational topic related to the products you sell, and award professional development hours (PDH) to the engineers in attendance.

PDH events allow you to:

• Demonstrate topic authority and position yourself as a valuable resource that engineers can rely on to help solve their problems.
• Create an authentic human connection with engineers, so they see real people when they think of your brand – not a faceless corporation.
• Build goodwill with engineers by providing something of real value to them.

To realize the benefits of reciprocity, you need to offer free PDH events. Sure, you can charge a fee to attend your webinar, but attendance will suffer. And those who do pay to attend will not feel obligated to reciprocate the favor like they would if you provided the webinar for free.

OK, so free is good. But there’s more to reciprocity than simply providing something for free.

The thing you provide needs to have real benefit to the recipient if you want to truly create goodwill. The old adage “It’s the thought that counts” doesn’t apply here. A mouse pad with your company logo on it is not likely to be perceived by the engineer as a highly cherished gift.

To reap the full benefits of reciprocity, you need to provide something of real value. PDH events provide two things that engineers truly value:

1. Knowledge
   Engineers crave knowledge. Most engineers are self-aware enough to realize there are gaps in their knowledge that need to be filled by experts. You can be that expert!
2. PDH Credits
   Professional engineers in most states need PDH credits to renew their PE license. Thus, earning PDH is very important to an engineer. The engineer will feel some gratitude to anyone who helps him earn the PDH credits that he needs to maintain his professional license.

Going back to the bicycle tire story… When the team saw how much money people were donating, they thought that perhaps they were taking advantage of the students. But, then they realized that this really was a valuable service they were providing on campus. The students were not being taken advantage of. They donated money because of a genuine appreciation for the free service provided.

Likewise, professional engineers who attend your webinar or lunch & learn will be appreciative of the knowledge they gain and the PDH credit they earn. They will be appreciative of the fact that you are doing something for them without any expectation of getting something in return.

If you reach out to these engineers at some point in the future, chances are they will feel some obligation to answer your email or return your phone call.

Of course, there’s no guarantee.

But who do you think is going to be more receptive to receiving your call? The engineer who attended your webinar and recognizes the name and voice on the other end of the line or an engineer that you cold call from a list?

If you’d like to chat with an expert to learn more about how to use PDH events to connect with engineers, book a free consultation.

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