Well, I have done this on every forum I have created. However, I have made fake members active until there were real people posting on the forum. When I open a forum, I do not want to to be bare bone. I can create a lot of topics but I cannot reply to my own topics, I need people to respond and creating fake accounts and letting them create posts and replies can show some activities. Even to buy posting packages on promotional forums, you need some members and activities. Therefore, I believe creating fake accounts while starting a community is not a bad idea.