Donuts in friends towns.
Does anyone know if there is a formula / pattern for how many donuts you receive from friends towns ? Some days I through all me friends (whether it gives event currency or not) and never receive bonus donuts for doing so, other days (like today) I only did enough to get me event currency and picked up 4 donuts in friends towns ?? Is this just a random occurrence or is there a pattern I am not seeing ??