Both are approaching inflection points in terms of audience growth (userbase) and business direction, and both appear to be stumbling.
Communities like MySpace only work when people come together to engage around a unifying, shared interest. MySpace has now grown so rapidly that it is difficult to detect a single shared interest, with the result that people are bumping into others with no discernible common interest.
Ordinarily, this wouldn’t be a problem if the community had an ability to sub-divide and spawn smaller communities (or sub-groups) of interest. But there is no facility within MySpace to do that. And I suspect that if News Corp tries to implement it, they will well-and-truly stuff it up – not necessarily because of any malfeasance on their part but, rather, because imposed organisational structures are inherently inferior to self-organisation.
The answer is to roll out new tools that lets the community itself self-organise…but that is a very scary proposition at a commercial level, as it introduces unpredicability into the revenue model.
The result is an increasingly jaded community that starts to look elsewhere for a more meaningful engagement (anyone notice how traffic on Facebook has started to boom…?).
LinkedIn has similar problems, but for different reasons.
They, and sites like it, treat social networks as uni-dimensional. But we each have myriad social networks – business, friends, community, family etc. Many of us don’t wish to clump our entire social group into a single environment, because they just don’t mix (by definition). Unless LinkedIn fixes this, it will have inherent growth limitations, and people will migrate towards other solutions.
At a commercial level, they are starting to encounter the same issues Friendster did (remember them?) immediately before it lost its mantle as the dominant business social networking service.
LinkedIn management are still trying to work out how to make money from the community they have enabled. In recent months, they have starting imposing limitations with respect to how LinkedIn community members can interact with their own network (presumably until they work out just how to clip the ticket.) Madness!
It is unlikely the LinkedIn service will suffer a mass exodus of users anytime soon – too many people have invested too much time arranging their network within LinkedIn. But LinkedIn has by no means achieved critical mass (or anything remotely close to it), so any actions on its part that impedes (or actively dissuades) users from building and nurturing networks is an obvious misstep.