Right, 100 trucks delivering 100 single items to 100 homes, or 100 consumers each making 1 trip to buy 100 things. It really depends on the details too much to simplify it so far.
Just anecdotally, I think the typical Costco trip is alongside trips someone would have taken already.
Go to work, take a 5 minute detour to stop by Costco for your prescriptions, gas, and groceries on the way back
It is more like 1 truck delivering 100 single items to 100 homes.