In the 1980s one of the big petrol companies (I think it was Esso) promised to be the cheapest local station at all times and did a pretty good job of it even though market information was much harder to gather in those days. Any price cut by the local competition was very quickly matched. What was the outcome? Higher petrol prices.
Competitors, once convinced of Esso's determination, became reluctant to cut their margins with no compensating increase in volume. So instead they tried to make more margin on the residual market share they kept. Of course, Esso followed them nearly all the way up and we ended up paying more than ever...
Whether this was before or after the marketing scheme in which Esso made the country ankle deep in faux crystal wine goblets I can't remember...