How does Fluther recommend questions?

I know Fluther recommends questions for us by comparing tags and keywords with our stated ‘fields of expertise’, but does it re-scan old questions when you add to the ‘fields of expertise’ list?

I just had a question recommended for me that is two months old. I haven’t edited my profile for quite some time, and I haven’t seen the question at all in the last two months. How does this process work?