Off-page SEO is an extremely important element in promoting and marketing websites, it is about search engine optimization from the outside of your website.
Getting links back to it is important. These are called ‘back links’ and they act as a vote to the content of your website.
Think of it like this; the more votes (links) you can get to your webpage the better, but, and it is a very big BUT, The links need to be good quality links, this is more important than quantity it will reflect in the rank in search results.
It isn’t all about backlinks, take a look Google Local Business Pages, it is crucially important for you to be connected with Google Plus and Google maps, this is what off-page SEO is about.