Ever wondered how many ACTIVE collectors there are in the United States?

[Exhibitman]

I think you meant exclude modern and postwar collectors. That would cut out the majority of 'serious' card collectors for sure. How would you handle those who collect across the board? The # of prewar-only collectors is certainly a fraction of the total number of even the hardcore collecting base. I mean, I collect across all eras. I have 19th Century cards and I have 2018 cards. Do I count into the prewar census?

For some issues I suspect that even 100 collectors would be an overestimation. Take Exhibit cards for example. I think I know most of the serious Exhibit collectors due to feedback on my book and years of trading and list comparisons, and there's maybe 50 of them at most across all subjects, plus a few dozen more who aren't ardent about Exhibits but who are doing sets of various types, mostly baseball and football. That's why it is an area that is reasonably priced, except for a few cards that have crossed over to popular collecting (e.g., the 1925 Gehrig RC, 1923-24 Ruth) . Even the Ruth and Gehrig cards are reasonable as compared to candy and gum issues.