Seth Godin, the famous marketing guru, once said, "Ideas that spread, win." He's right about that, especially on the internet where websites that get more valuable with each new user can spread extremely quickly.

Some of the largest, most successful websites online today got that way because they were inherently viral. Facebook and Twitter are the obvious examples, but less popular examples include Hotmail, Zynga, and Tagged.com.


When virality is done right, it results in lots of sign-ups and, ultimately, lots of revenue.

But there's a code to crack, some sort of mystic art or science to the whole process--right?


In this blog post, I'm going to pull back the curtain on viral website marketing and take the mystery out of how others have done it successfully and how you can too.


Study What Has Worked in the Past. I mentioned Facebook, Twitter and a few other examples at the beginning of this post.


Check out ProductPlanner.com for a visual, step-by-step overview showing the invitation / sign-up flow of all the most popular services that have grown virally by new users inviting other users.


Also, don't plan to be the next Facebook. Instead, be original, be different. Facebook is Facebook, not what your product or service should be.


Plan out your "viral loop." Draw out the steps for how virality will occur on your website. For example: person gets invite, person clicks link, person signs-up up, person imports email address book, person invites friends, and so on. Product Planner also allows you to plan out your loop visually.

Make sure there's a clear incentive. Without a good reason to spread your website or your content, your website traffic and sign-ups will not grow.


For instance, if you write a blog and your content is extremely valuable and original for the target audience that's reading it, visitors will use that "Tweet Button" that you have floating next to the post.


But that's not a very powerful incentive to share, at least not as powerful as it is with Skype.


With Skype, the service becomes inherently more valuable the more of your friends or contacts that are on it.


Hence, you have to get your friends to sign-up for the service in order to increase its value to you.


It's all about the numbers. There's no way to know if your website is growing virally unless you pay attention to the rate at which people share your content or invite others to the website.


One recommendation is to calculate the "viral coefficient." This is the number of invitations sent out per visitor on your website multiplied by the sign-up rate.


Refine the process. Finally as you watch the numbers and observe people sharing or inviting others to your site, keep experimenting with new ideas.


By adding or removing sharing-related features, changing the wording of your invitation process, or by removing steps from the viral loop.


With each change go back and study the numbers and observe whether or not the viral rate of sharing or sign-ups have increased.