One of the nice things about social networking sites is that they all seem to come with free badges and widgets. You can use these badges to promote your site. Some of them even let you customize what you place on them or choose the colors so that your badge will coordinate with the rest of your site.
However, with so many badges and widgets from different sites to chose from, there is always the chance that you can place so many badges on your site that they become overwhelming. You don't want to clutter the sidebars of your site or blog. Too many badges are overwhelming for the reader and often leads him/her to not click on any at all. You have to be selective in the ones you choose to permanently display.
For example, on Facebook alone I have the ability to create 7 different badges -- 1 for my profile, 1 for this blog's page, 1 for CBAY Books' page, and 1 for each of CBAY's different books' pages. Now if I place all 7 of those badges on my sidebar, they would just get lost. Instead, I just placed the most relevant Facebook badge -- the one for Buried in the Slush Pile's page.
The only other widgets I have on this page's sidebar all relate directly to this blog. Remember to place your own badges sparingly as well.