i have been reading these blogs and people keep saying how much of a mystery the supply/food drops are when in fact it has actually already beeen revealed. in season 3 when kate, sayid and lock go to the flame station where mikhael worked, sayid found a whole bunch of manuals on the food drops and how to order them. They made it pretty obvious with the big letters. no doubt mikhael was ordering the food for the drops. he had a massive sattelite on his roof. had to have it there for some reason.
but why were they dropping food even though there was no others to collect it? The others always knew the survivors were on the island and ben was at the flame the day of the crash. he probably ordered mikhael to give them food, because as mr friendly said "the only reason you're on this island is because we let you live here"
so look for the episode when they go to the flame and when sayid goes under the building, you will see the manuals.