If you don't watch FOX after its race coverage ends, there's no reason you should have heard of it. It's a network marketing program to get people to watch their race coverage while almost completely failing to mention the actual race itself, apparently by design. It's mostly used in promo spots during other FOX sports broadcasts.
Imagine something like, "We have this really cool thing happening the first weekend in May, and you should tune in because all the cool kids who drink Ol' Grand Dad will be watching, and have parties, and, and, ... oh, and there's a horse race too."