San Francisco struck 544,375,000 cents in 1969, 99.99999% of them are worth 1 cent. This year was also very very commonly found with
Machine Doubling. This is why so many people get excited thinking they have found a windfall.
Another problem with this date/mint is that since
DDO #1 is so rare and valuable, and
Machine Doubling is so common, it makes it very difficult to get any consideration as to whether a coin thought to be a possible
DDO might be one. There are at least two different
DDO's known, the big one and one very minor one. But if anyone posts a coin and asks "Could this be
a DDO?" most everyone looks, sees it isn't
DDO #1, and automatically says NO without any other examination or consideration. There is a difference between the question "Is this the
DDO?" and "Is this A
DDO?"