As per my opinion off-site is also a very Important one next to On-site optimization. some of the off-site seo techniques like:
1) Directories submissions,
2) Social Bookmarking submissions,
3) Blog commenting,
4) Article posting,
5) Social network sharing and soo on
These all are very important in getting Quality backlinks to our websites and also increases the traffic to our website. In simple ways i can say you opp-page optimization is what you do outside the website to get ranking.
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