If there are not many, many hundreds of thousands of collectors, who's buying all those stamps?
One way to measure the health of the hobby would be to measure things that are public & visible & (relatively) easily valued.
ebay, shmeBay ... consider the total sales/marketing expenses of our little industry:
- there are significant IRL auctions every week;
- there are significant shows every month;
- there are dealers running full-page print ads (that are presumably paid for out of their operating margin);
- there are people collecting salaries from those auctioneers & dealers & supply houses & ...
All of these things (with trivial exceptions) get paid for out of the operating margins of these companies.
And all of that money comes from markups (etc) on sales to collectors.
There's a Master Degree to be had estimating the economic superstructure we're supporting.
Cheers,
/s/ ikeyPikey