A club can only be popular if the subject is popular. For example, the Harry Potter spot (on which this totally unrelated pregunta is) is on the subject of Harry Potter, which is already popular outside of fanpop.
Do NOT beg people to join. Just wait patiently, subtley tell your friends, make the spot as interesting as tu can, and watch the fans come.
1. Discreetly tell people about it (for example picks "Will tu please registrarse my spot!!1!" wouldn't fall in this category, enlaces to spot and muro posts maybe would). 2. icono and banner can make your spot beautiful. :) 3. Add content to your spot .