Bambi Francisco's email today from CBSMarketwatch digs into social networking applications, asking the inevitable:

"So, it seems that these social-networks are a natural extension of any the larger portals (those mentioned above as well as Microsoft's (MSFT) MSN, Time Warner's (TWX) AOL, and search engines, like Ask Jeeves (ASKJ)) as they move toward a more personalized search experience. The question is: When does Yahoo and MSN launch their social network, or some variation of it?"

She goes on to mention a new deal announced by LinkedIn, a SNA vendor *not* competing with search engines, but in the job site market:

"Separately, LinkedIn, which competes with online job sites, such as Yahoo's HotJobs and Monster WorldWide (MNST), is expected to announce Tuesday that it's partnering with DirectEmployers Association to help the 125 companies that make up the group, including IBM (IBM) and Sprint (FON), to hire employees. LinkedIn, which has 140,000 LinkedIn users (including myself), says it's facilitated more than 15,000 referrals."

Many observers argue that there is no market for SNA, per se; its just a feature, they say. But if so, it is such a major shift in how these services -- search and job sites, for example -- that it is potentially destablizing for the established market. LinkedIn could potentially force job site leaders to compete based on SNA-features, and capture serious market share in the meantime.