Note: This is a cross-post from http://g.garron.me/the-myth-of-duplicate-content
I think some webmasters who follow this blog might be interested in reading it here.
After reading this post
I finally understand better what duplicate content means and how it can really affect your ranking in search engines. Maybe as many webmasters out there, I was thinking that if I receive for instance a guest post that the original author have also sent to other three sites, I would be penalized. But that is not the case, and that actually is only one article in a site, so even syndicated content like, what can be found at: http://crunchbanglinux.org/planet/ is not harmful for any site, not the syndicated, nor the syndicating. As the first is the originator of that content and the latter have more content than the found in only one site, as it is syndicating from various sites. So while the site itself (http://crunchbang.org in this case) is not penalized, it would be rather not easy to find the content of its planet section in SERP.
That said, I will sleep better from now on.
As I am also having this site, http://tumblr.garron.me syndicating content from this site http://g.garron.me and this other http://www.go2linux.org, as a summary of my posts in these two sites.