There are a lot of social bookmarking sites like digg, folk, delicious etc. These are very effective sites to get higher rank.

Twitter is the best, if you have followers.
Pinterest is awesome, If you know its bookmarking secrets.
Reddit is amazing, If you follow some simple rules.
Stumble upon works, If you know some tricks

Simply go to source, I bet you, you`ll never need to ask this again from anyone.

Source(s)

technologydip.com/blog/the-best-soc...