An Event can be any SEO-related action or change that you want to track. It could be on-page changes like optimizing a title tag, or an off-page tactic such as a new link building campaign, or big PR push.
Tracking Events shows you what’s working to move your site up in Google or Yahoo.
Once you start tracking an event, we record the change in keyword rankings and organic traffic to measure the effect of the change.
Once you've created an event, you can run your first correlation test and you'll start to see the output of your tests so you can clearly see if your SEO is working: