People always ask me how to make messages "go viral."

Every business needs to get the word out, every leader wants her ideas to spread more.

So I talked with Jonah Berger, the leading word-of-mouth scientist, to get answers. Berger, a Wharton professor and author of Contagious, gave me a six-step method to drive people to spread the word.

Here's what he told me:

1. Social Currency

People love to talk about things that make them look good. The promotion they received, how well their kids are doing in school--or the time they got upgraded to first class. So make them feel like insiders, or give them remarkable information, and they'll tell others in order to make themselves look smart and in the know.

2. Triggers

Top-of-mind means tip-of-the-tongue. Ever wonder why people talk so much about the weather or what they had for breakfast? The more people are thinking about something, the more likely they'll be to tell others about it. So link your product or business idea to prevalent triggers in the environment--objects, ideas, or topics that come up frequently in conversation anyway.

3. Emotion

When you care, you talk. If you're excited about a piece of news, angry about a decision, or amazed about a discovery, you're much more likely to tell others. So focus on feelings rather than functions. Find the strong emotions behind any message you want to take viral.

4. Public Availability

People tend to use other people for information. What restaurant is good? Which service provider should I adopt? You look to others and assume that if many people are doing something it must be pretty good. But you can only imitate if you can see what those others are doing. So, the more observable behavior is, the more likely it is to catch on. If you create a campaign or idea that is easy for people to show, it will grow.

5. Practical Value

People don't only want to look good, they also want to help others. So the more useful a piece of information is, the more it will be "shared" on social media. Discounts, travel recommendations, or articles about the best sunscreen to use all get passed around because they're helpful. So, highlight incredible deals or useful tips and more people will pass it on.

6. Stories

Stories are the currency of conversation. No one wants to seem like a walking advertisement, but they will talk about a product or brand if it's part of a broader narrative: How a new software cut billing time in half, or how a company sent out a replacement product the next day free of charge. So, build a "Trojan horse" story, one that carries your brand along for the ride. Make your message into an enjoyable tale, and you can be sure it will be told.

Take into account a few of these principles as you create your marketing strategy, and you'll optimize your chances of "going viral." Take them all into account, and you'll get as close to a sure thing as I can fathom.

Before I end, I'd like to hear from you. Which if these concepts do you think is most important in order to create viral content? What is your favorite viral campaign? Let me know in the comments section below.