This is the story told by NPR's Planet Money podcast. Apparently, as the company was trying to figure out who was buying its cars, the marketing folks discovered that gay and lesbian people were a large segment – along with all those outdoorsy types. The discovery led to subtle advertising directed specifically at what we now refer to as the LGBT community, which in turn led to more sales to gay and lesbian consumers. There were other components to Subaru's sales strategy in the '90s, but this particular campaign was an important part and quite successful. Thanks to that success, today we still have Subaru around building reliable, all-wheel-drive transportation, as well as rally-inspired sport compacts.
There are of course many more details, but we don't want to spoil them for you. For the whole story, you need to head over to the Planet Money site and listen in.