(I've previously posted this on a private mailing list, so stop me if you've heard this before.)
In the early nineties I worked for Thalion Software, a company which was somewhat legendary in Europe on the Atari ST and Commodore Amiga platforms. Because it was founded by and employed many former demo coders (such as me), their games were known for their high technical quality. Around 1991 we were approached by Rainer Bopf, a colonel from the German air force, who had written an Airbus A320 simulator for the Commodore Amiga. To the extreme demo coders that we were at that time, the technical quality was, bluntly speaking, bad.
But our managing director at the time saw something in it. He made a licensing deal with Airbus, Lufthansa and Jeppesen, the company making the aviation maps used by actual pilots, and marketed the game as a serious commercial (ie non-military) flight sim, aimed at an older audience, who wanted their fantasies firmly rooted in reality. The game came in a heavy box filled with a big manual and aviation maps. It became a huge hit, so huge that the MD at one point got up every two hours at night to feed the disk duplication machines which were running in his basement at home with fresh floppies. It became so huge that one weekend, the developers (us) had to come and help fill the boxes. So there we were, any of one of us top people in our respective domains, filling boxes. (If you ever hear me saying that "I did pretty much everything you can do in the games business", I am referring to that weekend.) If I recall correctly, the game sold over 250.000 copies, on Amiga and ST (and maybe PC), in the early nineties, mainly in Germany and the UK. There was even a players' conference in the UK.
One programmer, who is one of the most talented 3D engine programmers I know (he wrote the 3D engines for No Second Prize, Extreme Assault and Incubation), had to port this game to the Atari ST. I shared an office with him at the time. Do you know that Gary Larson cartoon with the devil showing the guy into a room in hell full of idiots with banjos, saying "And this is your room, maestro"? That's what that was like. It was heart-breaking.
That was my first experience with what I call the model railroad market segment. That (and all of the above) was not in any way derogatory, bitter, or sarcastic. It's a passionate group of people with lots of disposable income, and this game, with its realistic depiction of commercial air flight, spoke to their hearts.
Links: Rainer Bopf's homepage, which I've just discovered. It contains screenshots and the history of the Airbus A320 flight sim, which continues to this day. A lot of it is in German, but you'll get the picture.