AryanBiz, i have been using business social networking sites with great success over the past 2 years.
The golden rule of all these sites is "Know, Like and Trust".
I have seen so many members at these sites mess up their changes of success simply because they approach it wrong.
They don't setup proper profiles, they upload a photo or avatar of some superhero, and their 'about' section is not about them, just the business or product they are trying too flaunt.
Now would you buy a product from someone in a store standing there in a ski-mask, i don't think so.
Social networking for business is here to stay, and if you want to see extraordinary results, you had better do it the right way and put the effort into it. I mainly use these sites to brand myself and the opportunities i promote.
I do get some excellent results, percentage wise i would say +/- 30% of my traffic and leads come from social networking sites.
That might seem high or low depending how you look at it, but i do put a lot of effort into these sites.