I have been doing some thinking here lately

I am currently offering my services to basically anyone, huge range. What about specializing in being a Virtual Assistant for Virtual Assistants? So many of the VA's I speak with on a daily basis, have mentioned the need for a VA. What do you think?
My current clients consist of: Coaches, Web Developer & IT support business. I do their invoicing, calendar management, making sure everyone has the proper documents to begin the coaching process, feedback forms, signing contracts, data entry, spreadsheets, follow up emails & phone calls. That's just to name some of what I do. All of the items mentioned are tasks VA's need done as well.
My question is this..Do you think there is need for this niche? I know they're some very successful VA's around here, would this be something you would consider? I'm not just talking about outsourcing a few projects here and there..
I'm interested to hear feedback on this!