movies and series... u will need excellent location with no much competition coz in most estates there are 2 on every corner.
try the pop corn... it has potential for growth as kaka pointed out. even if u don't have time to be there all day, just the pop corn alone u can trace how much the sales are and progress to other items.
be wary of wajanja employees who come with their own raw corn and sell, so jioni urs is still intact and little money but he's been selling his all day.
pull surprise random visits on such... it'll sort them out.
I am an optimist. It does not seem too much use being anything else. ~Winston Churchill