i imagine using the addthis buttons take away valuable linkjuice… is this correct…? when search engines crawl the addthis button it will leave my site and head to addthis.com … therefore what about if i add no-follow tag?
I dont think adding add this button will harm your seo ranking.I have found many high pr sites and blogs using add this button.
Given the profusion of ‘share this page’ links that seem to cover most websites these days, with some offering up to a dozen bookmarking services, I very much doubt that Google will consider those links as being as important as a normal link to another website. Google is smart, and they aren’t going to be fooled by links to social bookmarking sites!
Because google is not updating the visible pagerank on internal pages very often, I don’t think it is possible for us to make an informed decision either.
From a pure pagerank standpoint, you want more links coming in and less links going out. With regard to outbound links, the more you have, the less you distribute to the internal pages of your site.
However, its not all about pagerank.