clipped from: radar.oreilly.com   
One of the most interesting parts of running a large website is watching the effects of unrelated events affecting user traffic in aggregate.
John Allspaw recently created a WebOps Visualizations group on Flickr for sharing these kinds of graphs with the confidential information removed. Here’s an example of a traffic drop seen both by Flickr & by Last.FM that coincided with President Obama’s inauguration.
John Allspaw shows drop in web traffic to Flickr during Obama inauguration

Similar traffic drop on Last.FM seen on the right

Traffic Drop to Last.FM during Obama inauguration on right

Google saw a similar drop as well

Traffic Drop to Google during Obama Inauguration

Was it because everybody went to Twitter?

Traffic Spike on Twitter during Obama Inauguration