Social Bookmarking

The 3 advantages to social bookmaking are 1) that if your computer crashes all of your bookmarks can be saved online to a site like Delicious. 2) If you can't remember a website and you're away from your computer you can find the site by going to the site where you saved your bookmarks. 3) If you can't remember your passwords for different sites, you can save the link as private and add notes about your usernames/passwords and then will only be able to see it when signed in.
The 3 disadvantages to social bookmarking are 1) there isn't a standard for tagging. This might cause people to become very confused whilst searching through tags to try and find something because not people might not be consistent with their tagging standards. 2) Spam.  Since people can just search through different subjects or tags in order to find thing faster, spamming is increased. This would not be an issue if people would just receive links from people they have subscribed to. 3) Due to the popularity of social bookmarking some users have started using it a an SEO (search engine optimization) to make their website rank higher. They use them (social bookmarking sites) to tag the page multiple times.

The Differences Between Social Bookmarking and Rss Feeds

Rss Feeds are used to distribute content rapidly. So all one has to do is look at the feed and then they can see the updates. On a bookmarking site, you just save the URLs. It doesn't list updates on the site. On a side note, one could always link their RSS Feed to their social bookmarking site.