If you use these social networking sites to drive traffic to your sites then which one has sent you more visitors? Please post here..
StumbleUpon is better for me Also, if you are confident in the quality of your article, advertising on stumbleupon can be beneficial as long as people give you the thumbs up.
Stumbleupon and delicious can bring traffic for the site. The website del.icio.us (pronounced as "delicious") is a social bookmarking web service for storing, sharing, and discovering web bookmarks.del.icio.us has a "hotlist" on its home page and "popular" and "recent" pages, which help to surface interesting content and make the website an effective conveyor of popular internet memes and trends. StumbleUpon chooses which new webpage to display based on the user's ratings of previous pages, ratings by his/her friends, and by the ratings of users with similar interests.