It finally happened. After all that hard work with building backlinks, writing keyword articles, and optimizing the metadata, the traffic on one of your websites suddenly receives a sizable spike in organic search traffic from Google. You couldn't be happier. Then, just a few days later, the traffic plummets back to its old level, if not even below that.

What the heck happened?

Over on the Webmaster World forum (via SE Roundtable), user sftriman had exactly that experience. He got excited that he finally got "past the Panda slap," only to see his traffic drop "like a sack of stones." This phenomenon is known as the Google traffic tease, but why does it happen?

The easiest answer is that traffic is known to fluctuate wildly for all sorts of different reasons and it can be difficult to pin it down to just one. That said, it's quite possible that something odd here and there could give you that spike, only to take it away. For instance, if one of the images on your site suddenly ends up near the top of image search results for a popular keyword, you'll see that effect. As more images come in to usurp you, your image gets buried and the traffic goes away.

It's also quite possible that you hit upon a timely topic either knowingly or otherwise. Maybe you blogged about something and then it happens to be the topic of the Google doodle. People search for more information about the the topic and you get that traffic, which would then quickly disappear when the doodle is no longer there. It might have something to do with Google too, like bot activity that wasn't filtered properly. Or it could be Panda.

Have you experienced this with your sites? Were you able to figure out the source of the increased traffic and, more importantly, were you able to duplicate the results for another spike in organic traffic?