I set up a link blog and a collaborative bookmarking site for our tiny geek community. My friends have initially been slightly confused by the conceptual similarities. So here are a few general guidelines to provide a clearer distinction of use cases.

Both tools are relevant for posting links with no significant value added by the poster. If there is value added by the poster in the way of analysis, context, story telling or anything else, a traditional blog entry is a better choice.

A social bookmarking tool must focus on resources that the user might want to come back to in the future, or that he thinks that his friends might be interested in one day. The accent is on easy recall through various means of discovery such as search, feed reading and folksonomic exploration.

By contrast, a link blog focuses on immediate sharing. It is the place to show off the spectacular, the anecdotic, the exceptional – novelty items that you want to share with your friends but whose future recall value for practical use might be low.

The motive for link blogging is not just altruistic : posting in a link blog is also a way to elicit reactions to the content you discovered. And that is why the community gathered around your link blog is important : you want to gather contributions from the people that matter to you. And if you have enough feedback, then there might just be enough new material to warrant more synthetic capitalization in a proper blog article.

As you can see, although the niches of social bookmarking and link blogging in knowledge management do overlap a little, they are definitely distinct and educating the users in extracting the highest value from them is worth the effort.