List of top social bookmarking websites

Hello everyone, today i am putting a list of top social bookmarking websites.

First understand what is a social bookmarking site and why it is necessary to bookmark your blog/website here?
list of social bookmarking websites
Social bookmarking website:-A social bookmarking service is a centralized online service which enables users to add, annotate, edit, and share bookmarks of web documents.
Why it is necessary?
Most online users use social bookmarking sites to search content.They gives more preference to social bookmarking sites over search engines.So,it is necessary to put our content on these bookmarking sites for driving traffic on our blog/website.

Here is the list of top social bookmarking sites:-
google bookmark
yahoo bookmark
pinterest
tumblr
stumbleupon
metafilter
LinkArena
akonter
social marker
digg
delicious
xing
weheartit
fancy
bitly
flipboard
techmeme
tapiture
scoopit
bloglines
netvouz
newsvine
diigo
sociopost
timejoob
examiner
blinklist
fark
plurk
dzone
livejournal
linkroll
slashdot
bizsugar
Hubpages(squidoo is now apart of hubpages)
bibsonmy
tumblr
stumblrupon
metafilter
LinkArena
wirefan
bookmark-manager
pearltrees
blurpalicious
6buk
backlinknow
bestlinksworld
bestplace4links