I never collected the "Dark Shadows" cards, but my brothers and I did collect the "Star Wars" ones. In fact, we had a couple of complete sets. I can still see the 7-11 in New London, CT, where we bought most of them. -And all of that bubble gum!
-Of course, they got thrown out in one of our moves. And, of course, some "mint condition" sets are now fetching a pretty penny on e-Bay and other places. Ah, well.