I Don't think any one is worried about getting all at one place as it is very difficult. People will concentrate more on how many followers they have, May be it is on facebook friend list or twitter follower or blog subscriber. It is all going to be reputation management and networking. It is going to be more of whom you know and how well you know them.
Each service is so distinctive, some poeple may not have a blog and still very popular with Facebook/Twitter.