[Shelley_c]

For me personally, I would expect to have 100 registered members in 4-5 days but every forum is different and there's no set amount of registrants that have to be made within a specific timeframe.

In short, Every forum is different, and many factors are in play with regards to the amount of registrations whether it be, to lazy to register, whether the content submitted on your forum appeals to the person prompting them to register. There's just to many factors to mention but all in all I would say there's no specific amount though each admin can set their own goal whether it be for a daily, weekly, monthly timeline to the amount of registerations they are expecting/setting.