StumbleUpon is a tool that helps people discover and share sites on their particular interests.
It's different from a search engine in that the pages they serve up have been explicitly recommended by your friends or one of over 15 million other websurfers with interests similar to you.
But the reason you should be using it is that you can submit pages and sites of yours for free for others to share.
You can join for free by filling out the profile at StumbleUpon or you can connect your Facebook account to StumbleUpon.
It's a quick process to get started, and then you can begin Stumbling pages and sites.
After you have created your account, you can Stumble sites at StumbleUpon.com or use a toolbar to do it with your browser.
I would suggest going relatively broad with the topics you choose to describe your submission.
As you might imagine, the more popular topics get more attention through StumbleUpon, but it's also a great source for free, targeted traffic for niche sites.
Thanks for this post. I am relatively new to SU. How do I use it to promote my affiliate links.
This post describes the process.