That's fair. However I was making the comparison with the general population, and yeah, knowing that websites exist outside the big 3/4 ones they use is already a feat for them.

The odds are still very low for a Pillowfort user to know of us, but have to be a huge multiple of the odds for a typical Tumblr user.

By way of example, I made a Pillowfort account myself when the Tumblr porn ban happened. So there's at least one. (Although I didn't stick around there much)