It is very similar to how retailers want to expand markets. They no longer have to go door to door to make a sale but other means to get similar results. A good example is someone who joins a networking site, joins a discussion, sees an opportunity and then takes it. If that member was able to provide quality service, other people will be interested in availing the same products or services as well.
Recruiters have also found better uses for the social networks because it enables them to find the right people whenever there is a job opening. Instead of waiting for an applicant to send their resume after posting an ad in the print publication, they can get referrals of people who are qualified to take on the job without spending any money.
There are some who say that the popularity of social networks will eventually kill web searching. But experts in the industry say that this is not possible because Google which happens to be one of the biggest search engines around and has market capitalization bigger than that General Motors or Ford will not allow that to happen.
While there may be new features in these social networks in the future, people will still have to use search engines when they need information.
Social networking sites are here to stay because aside from maintaining contacts with existing friends and making new ones, there are other things that members can do with it. It just takes someone to think out of the box to find some better use for it which will be welcomed by the public.