First of all, I want to thank you for taking your valuable time to read this post!  Persuasion is a fascinating topic.  It is used (and misused) in business and life everyday.  HBR had a very interesting article on the subject of reciprocation.  It reminded me of Michael Scott (from The Office) describing reverse psychology... but in this case, it is both real and effective!  I noticed the instance below that describes my "gift" of $5 to save the planet by reusing my towels when traveling recently.  I realized that this also saved the hotel more than the lame $5 credit but thought about how clever that approach was!  Enjoy the article, and keep your eyes open for new ways to affect behavior in business.  Let me know what you find... now you owe me one :)

You are more likely to invite a neighbor to the party you're hosting this weekend if they have previously invited you to one of theirs. You can be persuaded to leave the waiter a bigger tip if he places a piece of candy on the table along with your check. Fundraisers can increase the chances that you will make a contribution if they accompany their request itself with a small gift.

The principle is reciprocation: the psychological phenomenon in which we feel drawn to repay what another has provided for us first. An obvious idea, but understanding its nuances can enhance your ability to build stronger networks, create more trusting relationships, encourage long term collaboration and become more influential over others.

What is particularly fascinating about the way reciprocation works is the order of the exchange. Unlike a traditional "if you help me then I will help you" transaction, reciprocation requires us to take the lead and be the first to give in the hope that the recipient will play by the rule and respond accordingly. This isn't as naïve as it sounds; numerous studies have in fact shown that if we give first, those we invest in will very often live up to their obligations — often even more than when we demand the initial move.

A series of studies conducted by my Yes! co-authors Robert Cialdini and Noah Goldstein show how this played out in a business setting, looking, for example, at how hotels asked customers to reuse their linens. The study showed that when guests were informed that the hotel had already made a donation to an environmental organization, those guests were 45% more likely to reuse their towels and linens. This was compared to a standard approach in which guests were told that the hotel would make a donation only if they reused their towels first. Compared to this standard incentive-based message, the"give-first" strategy resulted in a more desirable change in guests' behavior, more environmentally protective outcomes, and increased cost savings for the hotel.

The same holds for other situations that require an element of persuasion. In another series of studies, researchers sought to persuade business executives to complete health and safety questionnaires about their organisation. They found that the inclusion of a $5 gift doubled the response rate compared to the promise of a reward of $50. Not only did the gift trump the reward in terms of response, success came at a tenth of the price.

However, the key to the reciprocity approach lies in your response to the message of thanks for the initial favor. How you phrase your "you're welcome" can determine your footing for your own request down the road.

Don't worry, I'm not suggesting that "Yes I did help you out and now you owe me" is the right way to go; of course you'll just be branded as someone whose help is best avoided in the future! But the much more common response —"Hey, it's no problem, I was happy to help." — isn't quite right either, because it fails to take advantage of the very moment when you are at your most persuasive: the moment immediately after someone has thanked you.

Instead, you should highlight the help and assistance you have given in a specific way that will increase the likelihood that it will be reciprocated fully in the future. For an individual, that means "Happy to help — I know how valuable it would be to get your help if I ever need it." Or, "No problem — I know that if the situation were ever reversed, you'd help me."

And in a more formal business setting, if you're looking to secure future business opportunities from your currently satisfied customers, it's: "You're most welcome. It's what we at XYZ Corp. do for our important customers" or "I am glad that we were able to resolve this issue. It's the sort of thing you can be assured of when you deal with ABC Inc."

The key to optimising the principle of reciprocation, then, is a two step approach: give help or assistance first and then be sure to position your help as part of a natural and equitable process of give and take.

And by the way, if you found this article helpful, please let me say: "I am delighted that you found it so useful. It's the sort of thing you should expect from the blogs on HBR.org."

Steve Martin CMCT is co-author of the New York Times Bestseller Yes! 50 Scientifically Proven Ways to be Persuasive and Director of INFLUENCE AT WORK UK.