Social networking links
In the link building world you may have heard these 2 terms, nofollow and dofollow or follow links.
Nofollow - means you do not get a link vote for your site. The Google bot will not crawl the link and won’t pass any votes onto your site. (the link doesn’t count)
Dofollow link instructs search engine spiders to follow this link. Following a link can give the site owner additional link votes. (the link counts)
You still with me? Whaaaa…….
Take Facebook, the single most important social network. Links from Facebook to external pages are nofollow links. I am not total convinced that this true. Some other social networks use follow links. There are some nofollow links between Google+ accounts but the external links are follow links. Myspace provides nofollow links while LinkedIn provides follow links, but in both cases, they're not direct links to the reference sites.
Some social networking sites evidently tried to decide which links should be followed and which shouldn't. Digg says that they provide follow links in cases that the story has reached a certain popularity. Twitter used to use nofollow links but seems to have switched to follow links.
Is there SEO value to social networking nofollow links? That is, will the search engines consider the links for ranking purposes? Will social network links help push your site up in the search results? In theory, no.
The major search engines, Google and Bing, ignore nofollow links for ranking purposes. They may actually follow the links in some cases but both search engines claim they do not use nofollow links for ranking purposes.
So is social networking useful or not for SEO? In some cases, definitely useful as you'll get follow links. The official position of the search engines is that you should go ahead and promote your site in the social networks because links bring traffic regardless of search results ranking. A well-executed social networking campaign can help a website get traffic directly bypassing the search engines. Social networking is no silver bullet and doesn't work very well for all types of businesses.
So what to do? Get a Facebook and Google+, Twitter and Linkedin account. You'll also want to use the usual social networking share buttons and try to encourage people to link to you from their social networking accounts.