What with all the attention on virality in closed networks like Facebook, we think it’s timely to remember that search engines can still throw tons of traffic without requiring users to spam all their friends or infecting them as coughers or zombies. But search traffic can only go to public webpages, not containers or canvas pages in a larger website, so while you may be huge in Facebook, Google will never know it.

One month ago we launched a dog breed quiz. People answer 10 questions, and we tell them what dog breed they would be if they were a canine. If they forward it to a friend who takes the quiz, we report back to the both of them as to what their doggy compatibility is. Not surprisingly, our “viral factor” was pretty mediocre (.30) because on the open web people post links or send their own emails, and very little of it is trackable.

After a big surge, usage settled down to one to two thousand people taking the quiz a day. Then suddenly, last week, the quiz started ranking in Google search results, and now five to ten thousand people are taking the quiz a day. The viral factor did not change, but due to a higher ranking in Google, many more new people were taking the quiz. Better yet, these new quiz takers were inviting their friends to take the quiz, so our overall potential pool of takers significantly increased.

Search engine referrals are still hugely powerful and have created huge new pools of visitors we frankly didn’t expect to find us.

[Thanks to Dutch and the Central Coast Hound Pack for the photo]