Last summer, during a discussion of who should be our third relationship finder connection, I started rambling about unconnected family trees of various sizes. In the end, the decision was made to go in a different direction (and one that I have no problem with), but I still keep wondering if there is some way to get more information about unconnected trees, like listing them by size, or something like that.
What I said then was:
I can't actually see the data. Actually, I'm not sure that anybody would have the time or patience to do this manually, but if there were a script which could define clusters of connected profiles, I rather suspect that it would find something like this:
Rocks: A large number of profiles with no connections to any other profiles, started by people who signed up as guests, but never went any further with WikiTree, for whatever reason.
Islets: Another large number of clusters of 2-12 profiles where somebody has entered, say, their own immediate family, and maybe back a generation or two, but never built out any farther (whether because they haven't had the time, or the knowledge of the available tools, or what).
Islands: A smaller number of clusters of, say, 13-144 profiles where somebody has been pretty industrious, or maybe several islets have managed to connect with one another, but somehow haven't found a link to the larger family tree.
Subcontinents: Clusters of, say, 145-500 profiles, possibly several smaller clusters that have managed to connect with one another, but not with the larger family tree.
Continents: Clusters of 501+ profiles with no connection to the larger family tree.
The Mainland: I assume that there is one cluster which is massively larger than all the rest, and possibly even larger than all of them put together, and I rather suspect that A.J. is in that cluster, so that if you have a link to A.J., then you're probably on the Mainland.
Therefore, it seems to me that picking other relationship finders who are also on the mainland would be kind of pointless. (Well, fun, of course, but not really helpful. Once you're connected to A.J., you're probably connected to everybody else on the mainland.)
What would help, or at least encourage, people who aren't connected to A.J. is to pick relationship finders in continents, starting with the largest. In a sense, it doesn't matter who we pick on each continent, although picking someone notable would probably encourage people to at least run the test. And that way, somebody can console themselves by saying, "Okay, I'm not on the Mainland with A.J., but at least I'm on the continent of Doeania, because I'm connected to Jane Doe."
(Or, possibly, it may turn out that A.J.'s continent isn't actually the Mainland, but rather the continent of Jacobsia, and we'd need to pick somebody else as the relationship finder for the real Mainland.)
And then, of course, we can have challenges trying to connect different islets, islands, subcontinents, and continents to the Mainland. Connect an unconnected cluster, and get a "Bridge Builder" badge, or something like that. (I didn't mention trying to connect rocks, because I'm thinking that would be pretty hard to do, but anybody who managed to connect up, say, 100 rocks to other clusters would be my genealogical superhero.)
(And if you don't like those metaphors, feel free to pick one that works for you. I grew up on the water, so these terms just kind of naturally pop into my head.)