My Narva scenario's paid sales are at the same level, but since I left it as PWYW, it's about 80% of that. Both Rüdiaria Awakening and the Missing Baroness have reached 40+ sales, so i hope that they also hit copper best seller status by summer…
Looking at my sales, there is a core of 20-30 or so purchasers who buy adventures quite reliably, the rest kind of trickles in, with bumps upon release of new material (though with PWYW, it doesn't mean €£$¥).
Secrets of the Empire (1.5 years since published) - has sold 104 copies
Of Magic Condensed into Shape (22 days since published) - has sold 65 copies
Elder Magi, Volume 1: Audrey de Verditius (2 days since published) - has sold 11 copies
It looks, for now, like the Elder Magi is the worst selling item, so far. It certainly sold worse than I had hoped. But I am committed to the series, and will continue making them.
Things like this may have a long tail, I hope -- when you have the whole series, and people know they can come and buy something when they have the specific need for it. But it doesn't quite have the general use case of the vis sources...
Sorry if this has been asked and answered before, but for this other published material do the publishers generally provide a sample page or two, e.g. as a pdf on a website? I think it helps with sales a lot if more people have a good idea of what they might be buying.