I just do not understand the way system work. Because I have 90 posts but update only to 56 activities.
So I think it a certain number each time update. Like 42 will go to 56 and then go to xx ... Is that how it works? I am just curious.
imperatron and other users gave you a nice link to forum rules above, but not to be so technical: as a rule of thumb you might want to add 2 posts per day mon-fri, it is a nice compromise between not working too much and having your account rank increase as much and fast as possible