I’ve been reading a lot of Seth Godin’s blog these days. For all of the talk about new trends in marketing, especially Internet marketing, Seth’s messages provide a consistent foundation that is becoming more and more helpful to me… which is why what I’m going to say next may sound odd.

I think Seth missed a key point in today’s blog posting titled “Is viral marketing the same as word of mouth?”

While I’m hardly qualified to disagree with Seth, I think he omitted why word of mouth and viral marketing are different. Seth says:

Word of mouth is a decaying function. A marketer does something and a consumer tells five or ten friends. And that’s it. It amplifies the marketing action and then fades, usually quickly. … Viral marketing is a compounding function. A marketer does something and then a consumer tells five or ten people. Then then they tell five or ten people. And it repeats. And grows and grows. Like a virus spreading through a population. The marketer doesn’t have to actually do anything else. (They can help by making it easier for the word to spread, but in the classic examples, the marketer is out of the loop.)

I think that Seth missed a great opportunity to explain more about how the marketer can make it easier for the word to spread. A virus spreads because it has a built-in mechanism to replicate itself…. Consider the cold virus or the inimitable computer virus. A good portion of its energy is spent on replicating itself, ensuring that it will live another generation.

If you are a marketer hoping to create an idea virus, you must include some mechanism that helps the idea spread. You can’t just “do something” and expect the word to spread. That “something” must make it so easy, so enticing, so satisfying for the audience to spread the idea that they can’t help it.

Think about YouTube. They could have just set up a video viewing service with the traditional “tell a friend” button, what many sites depend on to generate word-of-mouth sharing. Visitors would have posted videos, and other visitors could have viewed the videos, then told their friends about the cool video that they saw by clicking on the “tell a friend” button…. But that wouldn’t have been nearly as effective as what YouTube actually did.

YouTube set up their service with the video hosting and the “tell a friend” button … and they added a feature that is so easy, so exciting that visitors can’t help but spread the word. They allow their videos to appear on other websites… and they make it easy.

Have people just told other people about YouTube and the awesome videos? Yes. But that’s not what created the hottest property on the Internet. That happened because YouTube included a mechanism… the viral component… that made it easy to spread their concept.

So that’s what I think is missing from Seth’s post. I’m looking for examples of viral marketing… idea viruses, if you will… that have been successful for smaller, start-up businesses. Share your link by leaving a comment. Yeah, leaving a comment is a little old fashioned… maybe you can help me find a better way.