The questions I got are mostly reasonable, but it seems they're always taken from a very small pool so I get the same questions over and over. Maybe you can track the list of questions already shown in the box (or some approximation thereof), to avoid asking them repeatedly? And yes, when you run out of relevant new questions it's probably better to broaden the scope than to repeat already-shown ones.
Also, it would be nice to get have a "show more" button, which uses the same algorithm but shows more than 3 questions.