The Las Vegas Motor Speedway opened for business in 1996. Two years later, the stars and cars of the NASCAR Sprint Cup Series rolled onto the 1.5-mile oval, located in the foothills north of the neon skyline. Every spring since nearly 140,000 fans roll into the desert for three days of NASCAR racing. This weekend they're back again for the Shelby American 400-miler.

Meanwhile, down on The Strip, those fans have stampeded into the casinos, eager to place their bets on that weekend's race.

OK, maybe not that last part.

Since the 1990s, NASCAR has moved from a regional to a national sport, passing the NHL in popularity and trailing only football, basketball and baseball when it comes to TV audience and merchandise sales. But the people who run the sports books of Vegas believe -- at least they hope -- that it is still in its infancy when it comes to getting some real traction in the betting world.