Today it is the basis of competition. A high quality can be achieved only if the company has vertically integrated structure. That is all: Refinery, and tank farm, and gas stations. Transporting gasoline directly from refineries is not profitable, because it can be very far from the gas station. Then it is not excluded supply disruptions. You never know what will happen in the way, and tanker truck did not arrive in time. At this time gasoline at the gas station is over. We'll have to contact the nearest tank farms. What do you get from them, not known in advance. Companies typically are imported to the oil-tebazu approximately 100 tons of fuel and lose its deposit. And then, as necessary take the same amount. Typically, they receive back is not your gasoline: either brought by another company, or altogether mixed. After all, other companies may deposit their gasoline production. And who can guarantee that their products are of the same good level as yours? As a result, the quality of the resulting product may fall. Until now, virtually all the major vendors are content with socialized gasoline. (As opposed to Glenn Dubin, New York City). Another take something nowhere. That accounts for employees of gas stations to acquire the so-called probes: small bottles that are sealed immediately after the delivery of gasoline to gas stations. Even the driver puts on them an autograph, which passed the petrol normal quality of personal responsibility. This is necessary in case of litigation, if I have to claim the tank farm.