StumbleUpon.com is a website that directs you to a random website that was liked by other people with similar tastes to you. Rating these website you like, automatically shares them with like-minded people and helps you discover great websites your friends recommend. It is quite popular with more than 1 million people using it.

Many webmasters have found that StumbleUpon is a great source of traffic, but few people know how StumbleUpon discovers their site.

StumbleUpon and Digg relationship

After starting a new website, one of my pages got posted to Digg. Although Digg did not rate the page very highly, I noticed a reasonable increase in traffic to my website.

In my website statistics, there was another site right below Digg - StumbleUpon. As my site was new, there was only a limited number of sites that linked to me. This is what made the traffic from StumbleUpon so intriguing. That is when I figured that StumbleUpon must add the top and newest sites on Digg to its list of sites.