Posting his comments I saw on another message board:
Per Roger Edmondson President of the Grand-AM series:
"Most of our track promoters do not publish attendance figures. I note that some series and some tracks do. Unfortunately, I also see and hear some numbers that are so out of touch with reality that they make truthful numbers seem woefully insignificant. I think sometimes folks lose sight of the fact that sponsors spend money and invest in events based upon figures that may very well be fraudulent. Newspapers and broadcast entities have to verify their distribution, listeners, or viewership, to justify their advertising prices. It would be real interesting to see the adjustments that would certainly follow any such requirement for truthful and verifiable attendance numbers in motor sports."