In general you are getting only link from profile section in social networking websites. It will certain help us to increase PR as well as SERP.In fact I have tried to search websites which will give you back links from profile section.
Backlinks from social media are important indeed, i know those links are no follow and they are not going to transfer any link juice but they can increase the traffic on your website, if they reach your website by a back link then by using a vibrant landing page you can generate the lead from those users.
I strongly prefer Facebook and Twitter to share or tweet my business website links. I found great results, which in turn positively influenced my websites traffic. Apart from social media, I also participate in various kinds of other activities such as forum posting, article submission, blog commenting etc for increasing my website backlinks.
In common you are getting only weblink from information area in sites. It will certain help us to improve PR as well as SERP.In fact I have tried to search sites which will give you backlinks from information area.