In my experience (and I get a book a week to review), books in the third category appear once a year or so. One such book is "Yes! 50 Scientifically Proven Ways to Be Persuasive" by Noah J. Goldstein, Steven J. Martin, and Robert B. Cialdini. This book ranks in the top 10 business books that I've ever read. The book is a collection of 50 short chapters that document an experiment usually in social psychology and then the ramifications of the findings. In a nutshell, the book truly does explain how to persuade. Here are some illustrations that you can probably immediately use in your business.

1. A telemarketing company increased phone calls to its 800 line by changing part of its script from "Operators are waiting, please call now" to "If operators a busy, please call again." Thus, the impression changed from idle operators waiting for the phone to ring because sales weren't great to operators too busy to handle all the business. This is called the principle of social proof: When people are uncertain, what others are doing influences their behavior. This is why we think restaurants with a long line to get in must serve good food.

2. Researchers found that the more options offered in a company retirement plan, the fewer people participate in that plan. Similarly, when experimenters offered only six flavors of jam, 30% of the people who approached the display bought any jam. When the experimenters offered 24 flavors, only 3% bought some. Therefore, instead of trying to offer every color, size, and price point of gizmo, you might want to reduce the choices to increase sales.

3. When Williams-Sonoma offered a new, improved, and more expensive bread maker, it found that sales of the original model doubled. This is because people like to make compromise choices that fall between the minimum they need and the maximum they can afford. Suppose you're a restaurant. Should you list the expensive wines or the cheap wines first? Probably the expensive ones because it will cause people to order the less pricey ones.

4. Which of these two questions is more likely to help you garner influence? "Who can help me here?" or "Whom can I help?" The answer is the latter. This is the concept of paying things forward. Most people have a deep sense of reciprocation and gratitude--indeed, most societies are built on these concepts. Hence, when you help people first, most will help you in return.

5. In an experiment, waiters gave candy with the restaurant bill to diners in three different ways: one piece of candy for each guest; two pieces of candy to each guest; and one piece of candy for each guest followed by walking away from the table and then turning around to give a second piece of candy to each guest. The results were: 3.3% increase in tips for one piece of candy; 14.1% increase for two pieces of candy given at once; and 23% increase in tips for the walk away and return with a second piece scenario. What's this tell you? Unexpected and personalized gifts are powerful motivators.

6. The authors of the book were able to almost double the likelihood that someone would donate to the American Cancer Society by adding five words to their pitch. The standard pitch was "Would you be willing to help by giving a donation?" The pitch that was twice as effective contained these additional five words: "Even a penny will help." Apparently asking for a little step in the direction you want is highly effective.

To illustrate the usefulness of the book, here is the email that I send when we add a person's website to Alltop.com. Alltop is an "online magazine rack" organized by topics that contains feeds from the top news and opinion aggregation sites.

I added the boldfaced text immediately after I read Yes! to increase the impact of this email by telling the recipient that the site is very busy, "even a penny" of mention will help, and many sites have added our badge. (Incidentally, all of what I added is true.) I am pretty sure that if you read "Yes!," you'll find things to change about your business too.Update: You'd probably enjoy this story of buying a rug in Turkey. (Thanks to Mitch Weisburgh for pointing it out to me.)