Socializing can be a good  marketing tool especially when you are socializing about your online business!  The first mistake people make are wasting their time on socializing.
  Socializing must be part of your online marketing strategy but you should not spend more than a dedicated amount of time on it.
   I try not to socialize more than one hour per day.
  Social Media can pull you in and you can waste a lot of time if you are not strict about the time you spend on these platforms.
Social bookmarking is basically a method I use to bookmark pages I like so that I can return to them later, without doing a search for them.
  The beauty of these platforms is that I can share my information with like-minded people.
StumbleUpon.
com- users can bookmark their favorite sites and they are also exposed to new sites in predefined topics.
  The user chooses these topics when they register for the service.
  Digg.
com- This community site allows users to submit content and rate it by Digging it.
  Users discover and share content by submitting links and stories.
Delicious.
com- Users can tag, save, manage and share web pages from a central place.
Mistake number 2 - Not keeping your bookmarking pages up to date.
  For marketing purposes it is important to keep these social bookmarking pages up to date.
  It will not help at all if you only bookmark a page there once year.
     Mistake number 3 - Incorrect Tags.
  The most important tip to remember is to make use of the correct tags.
Tags are the 'categories' in which the bookmarks are saved and it makes it easier for other users to find your bookmarked pages if they are tagged correctly.
These platforms are excellent tools to increase traffic to my site and I incorporate them regularly in my online marketing endeavors.