I've discussed the fact that the future of social networking sites is in offering value added services. LinkedIn is one the services experimenting with this, and now they have announced to start looking in an obvious direction for more value add.
"For example, LinkedIn may enhance its search function to make it easier to find site members with a certain minimum number of years of experience. Recruiters should appreciate that feature, said LinkedIn co-founder Konstantin Guericke. 'They're the people who are looking for the needle in the haystack,' he said."