There are some very good reasons to have more than one online profile. Social marketers discovered years ago that it is often a good idea to target business-related profiles to a specific demographic. Soon thereafter, entire applications were developed just for the purpose of Managing multiple accounts. I received a question today, however, about whether it would be wise for a particular client to start yet another online profile to manage a line of communication on a new product, or simply to expand a current one to cover that product. In this case, I advised the client I would recommend developing one of the current profiles to include marketing on the product. Here are some ways to know if you already have too many (or at least enough) online profiles.
Duplication: There may a point in which you really don't have enough content to really develop all of your existing online profiles, so you start cross-posting between the profiles. At some point, you may realize that there is no need to post basically the same content in several different places on a daily basis, and it may be time to consolidate.
Diminishing Returns: The first profile may be great. The second may be good. That third profile may start confusing your loyal fans and irritating everyone else to the point where they lose interest in all three profiles. Unless you have an independently thriving community to support each profile, the multples are probably not necessary.
The Voices Start Talking to Each Other (and Answering): Having multiple online profiles is one thing, but having multiple personalities online is not going to end well. It will wear you out, and confuse your readers. If you get to the point where you are your own most loyal reader and back-linker, it's time to consolidate one or more of your profiles, and develop one really good one.
Jennifer Pointer (e-mail) is in Tulsa, OK. She promotes a simple, a low-tech approach to effective online profile management, search engine optimization and social networking.