OK, I'm paraphrasing, but here's what the USA Today article said about the reason Richmond is not on the 2010 schedule.
Richmond drops IRL:
The IndyCar Series will not return to Richmond International Raceway, the track announced Thursday night. While the series? fees to host an event was among several financial factors cited in a review, consecutive lackluster races led to its decision according to a statement from the track.
"The series puts on good shows all over the world, but here at Richmond we just didn't have the racing that our fans have come to expect," the statement said. "Nonetheless, the IndyCar Series continues to run entertaining events at other venues and we wish them all the best for the future."
So, the cost of the race did not equal the benefit of the racing, in Richmond's eyes. That's the way it works.