I can see huge benefits of using social media in terms of opening up an ocean (never mind avenue!) of potential contacts, advisors, broadcasters and friends. However, I do think that a whole-approach view needs to be taken. For example, my professional networks currently include the following:
LISLink JISC mailing list; CoFHE JISC mailing list; LinkedIn groups; blog contacts
Often individuals posting a LISLink post will post a duplicate on CoFHE with the statement "apologies for cross-posting". This is because a large number of users are on both. I know that there are far more professional networks out there for librarians - how many people are on several / how many people are on some but not others? How many times are you unknowingly reaching out to the same individuals because they happen to be in both networks? I think that the number of profession-specific networks needs to be carefully managed so that we can still have the potential to reach a wide-range of professionals whilst not having to sign up to 20 different networks in order to do so!
Susie Dunn commented on Thing 12 raising concerns about whether online communities can create the same kind of relationships as face-to-face interactions. I share her point and also feel that online communities can only really have any chance of forging relationships if its users regularly interact.
Personally, I have found that setting up my blog as part of CPD321 has enabled me to expand my knowledge and reading by following other blogs and therefore given me an insight into varying professions.