This is one of those, “why didn’t I think of that?” The concept is so simple, overlay data such as Panda updates on top of your Google Analytics. This way you can see if a Panda update correlates will a increase or decrease in your analytics.

It also works with Quantcast, along with Google Analytics. The developer, Oren Sol, said more are to come.

The overlay data points include:
Google Panda Updates
Google Penguin Updates
Google Algorithm Updates
Holiday Data
Economic Data

Now, I do not know the data sources for the dates but I am sure they are close enough.

This comes as a free Chrome extension that you can download over here.

Here is the video demo:

Forum discussion at DigitalPoint Forums.

Note: This story was scheduled to be posted on this day, but was written earlier.