Slightly OT, but it seems like this company has several people on staff (the article mentions at least 3 developers, plus content people, plus the guy writing -

Slightly OT, but it seems like this company has several people on staff (the article mentions at least 3 developers, plus content people, plus the guy writing - so at least 5, maybe even 10 or so). Is it possible to sustain a business of that size on a tool as niche as this one? You need $1mln revenue a year at least just to stay afloat, and that's if you're in a not very expensive area, which would put you far away from your clients. How many customers could such a product have, and how much would they pay per year? I can't see how the numbers could work.