Earlier quoted context omitted.
They only have 43,000 members (stat from the same page), so that's 20 queries a day per member, which doesn't seem that crazy.
That said, 43k paying users is quite a bit of money, so if their team is small enough, that’s good enough, stable and steady income
Which I prefer; I got burned by Neeva shutting down shortly after they started (for a pretty mild version of the word "burned", it cost me very little, but it was annoying).