This has probably been mentioned several times before, but it seems to me that the most effective (perhaps ONLY) way to attract more serious
racers to this sim is by promoting it to people who are interested in real life motorsports. Most 'gamers' wont really be intertested because as a game, LFS is behind the times. However, most people who have a real interest in motorsports will get hooked on LFS because of the feel and the physics.
I discovered LFS on the
North American Subaru Impreza Owners Club forum in a post someone made about getting involved in wheel to wheel racing. People were commenting about how costly it can be just to get much needed seat time, and a few people brought up the idea of 'virtual' seat time via LFS or iRacing! This instantly appealed to me as I have an interest in one day getting involved in real life wheel to wheel racing, but I don't have the resources to get any real life seat time, but 'virtual' seat time could be a good, relatively inexpensive way to learn some of the concepts of racing until I can.
After I started using LFS, I talked to some of the people I play with on Midnight Club Los Angeles (xboxlive) about it, but most of them are gamers and not really motorsports enthusiasts, and were not interested.
In other words, this sim needs to be promoted on motorsports related forums and groups, not on other games.