I saw Korean singer group "TVXQ(동방신기)" logging in to AmebaPigg this morning!
Who are TVXQ?(via wiki)
This is not a fan meeting event. They logged in to the last as a general user.
It's an area for music events called "Pigg Dome" that they appeared(whole still pre-opening). Japanese artist "AAA" will hold virtual live next month here. AAA is a label same as TVXQ.
Many Japanese famous people use blog service "Ameba blog" becoming the base of AmebaPigg. Therefore they log in to AmebaPigg routinely as a general user. And their fan wants to see them and logs in to AmebaPigg.
I think that a form of this AmebaPigg can acquire a user than hold a one-shot event in virtual world.