I was contacted by someone who is a vendor to Microsoft about connecting on LinkedIn. I'm sure this guy is a good guy, and would be happy to link up with him. However, I think it dilutes the power of the network to link to just anyone, so I suggested that we get together for lunch, have a chat, and then connect up.
Some people on LinkedIn (or other social networking sites such as Ryze or Spoke) worry exclusively about the size of their networks. Now I will admit, network size is really important to the effectiveness of the network for its members. However, one should also look at one's social network as a web of trust. When someone asks me about someone in my network, I can give a real endorsement of that person. I think this is a dramatically stronger statement about someone than "They asked to connect to me on LinkedIn so I did...", and ultimately leads to better results.
So, I suggest that you be selective about who you link to on these sites. Avoid the temptation to grow your network just for the sake of growing it, because you may end up with a large network that is of little value to anyone.
Couldn't agree with you more. I too limit my connections only to those folks I have worked with or have known personally for some time. Even so, I have still turned down requests for connections if I did not think it was a good match - and have been turned down for requests. That's the beauty of LinkedIn.
I recently discontinued my Gold membership with Ryze due to the inordinate amount of noise on the site...and just stopped logging onto Orkut (never touched Friendster). If I want pointless chat, I'll just subscribe to AOL and log into a chat room. My point is, as these sites and this new industry has matured, so have my requirements for my social networking tools.