Ok, i can see how that advice could get confusing! Usually u post atleast one new item a day. After your initial set up that is...
But, i dont add new items every day, i couldnt possibly as it takes nearly a week to design a new pattern.
So either way, it can be good to stagger adding new products, but dont get too hung up on it if you cant, its not the 'be all and end all' of you shops sales.