I think a few years ago I estimated that TCDb had 70,000 members, so it's probably over 100,000 today
if someone pointed out that the statistic is available, sorry, I forgot where to find it.
I found something on line from 2022 that estimates there are 900,000 people in the hobby, round that to 1 million
So, 10% of the hobby are members of TCDb
The biggest "membership" of the hobby is probably ebay, that is to say, trading card hobbyists are more likely to use ebay than any other resource. Beckett is big, Blowout Card Forums seems to be big
I don't see a large amount of pre 2,000 scarce / rare cards in the collections of TCDb members. That is to say, as an example, if I search on 1998 Flair Showcase Row 0 [SN 100] typically only 1 TCDb member has any given card in their collection.
So what is to be deduced, concluded or estimated? Are these cards in members collections, but these members are set to Private?
Are TCDb members relatively newer to the hobby?
Are TCDb members trending to "lower end"
Are TCDb members tending to be, on average, vintage and / or Topps Flagship collectors, and don't care about other brands, newer cards, chase cards? [despite the fact that the site goal is to crowd source and list every trading card ever made, and associate an image of every card with the listing]
"Ability may get you to the top, but it takes character to keep you there." - John Wooden