This makes sense, of course, if one assumes that sales are tied to the country's population strings, because the customer can compare products only on a feature-by-feature basis. I believe it is significant, for example, that not since John D. Rockefeller sent free kerosene lamps to China has the oil industry done anything really outstanding to create a demand for its product. Not even in product improvement has it showered itself with eminence. The greatest single improvement-the development of tetraethyl lead-came from outside the industry, specifically from General Motors and DuPont. The big contributions made by the industry itself are confined to the technology of oil exploration, oil production, and oil refining.