Selective vs. promiscuous linking

One of the great dilemmas of online networks is what does a ‘link’ mean? Orkut offers several levels of ‘friendship’, whereas Friendster and LinkedIn just offer the binary option: yes i am your friend, no I am not. In several conversations with the LinkedIn team, I have heard them say very strongly that they want to promote a culture in which linking is meaningful–it indicates that you would actually pass on a request from the person to whom you link. Which, after all, is the whole point of LinkedIn and similar systems.

I agree 100% with this. When I get link requests from people I barely know, my standard response is:

I’m sorry, but I have a policy of not linking to anyone on LinkedIn with whom I haven’t developed some sort of significant business/personal relationship. This is nothing personal against you; this is a general policy I have to prevent me from getting deluged with requests and to keep consistent with the LinkedIn philosophy. I’m happy to get to know you in other contexts. I hope everything is well with you!

However, cultural realities — the desire to appear more popular and connected—may make it hard for LinkedIn to hold by this idealistic position. On their home page is this ad:

Get Exposure with CV Advantage
Is your resume lost in a sea of 1-2 page resumes?

Which leads to http://cv-advantage.com/CVA_LinkedIn/
, which says on it:

Don’t forget to send us LinkedIn invitations if we’re not already connected!

This is an invitation to the most promiscuous possible linking. If LinkedIn wants to make their system functional, and not have it drown in a sea of spam and unwanted requests, I suggest they make a stronger effort to discourage this sort of approach.

Which leads to a broader question: how can LinkedIn and similar systems create a culture and design a system to prevent such activities? by imposing a maximum number of connections? by grading people on % of requests which they accept? other?