O.K., I am going to admit that I first joined StumbleUpon as part of a strategy that the “SEO [Search Engine Optimization] Gurus” recommend to create backlinks to your blog content from social bookmarking sites like Digg and Reddit.  The idea being that the more links you have from other sites, the higher your SEO will be.  And, as anyone who has ever used StumbleUpon just for this reason will tell you, you quickly realize that you are just wasting your time because just by thumbing up your own blog posts you are not gaining any significant additional traffic to …