1. Linkedin mirrors real world relationships but does not change them. I assume the same is true on Facebook. More to the point, attempts to use LinkedIn to change real world relationships can be counterproductive.
There are a few people who seemed as if they were almost professional LinkedIn users. Their names came up constantly as connections. They had 500+ connections (LinkedIn shows the number of connections but only says “500+” above 500, so the person could have 5,000 connections). Most of those are bound to be weak connections. One example; somebody who contacted me by email years ago, it was not of interest to me but I must have responded to his LinkedIn request to connect. I really did not know this person. Another example; somebody I know well, but when I tried to use the connections he told me that during a job search period he’d networked relentlessly and entered every random contact into LinkedIn. He had effectively made his LinkedIn connections useless by ‘pollution’.
2. I can bye-pass the network and avoid paying the fees. The ‘professional’ users of LinkedIn tend to be sales people or recruiters. In other words people who network for a living. They are the ones who will pay the fees that LinkedIn charges
The problem is that ‘reciprocity’ (what goes around comes around; or you scratch my back and I’ll scratch yours) is missing. Sales guys sell, they don’t buy. If they simply use LinkedIn as a glorified marketing database, people will put up the barriers.
Sending a standardized mail through LinkedIn seemed like a cold and impersonal way to re-establish a relationship and ask for a favor. So I am not sure how viable the subscription revenue business will be.
This leaves advertising to be thought of. If they go for something similar to the Facebook ad model, that would go down like a lead balloon in this business community. It is possible that LinkedIn has the ‘magic monetizer’, the Adsense equivalent that turned a useful service into $ billions in revenue. I just have not seen it yet.