Well, checking my resolver statistics from a random day, it clocked about 8000 queries. Discounting some for mail, it leaves 7+k from my own browsing. That wou

Well, checking my resolver statistics from a random day, it clocked about 8000 queries. Discounting some for mail, it leaves 7+k from my own browsing. That would estimate your friend's public resolver at serving about 20 users, though I guess could be anywhere between 1 and 300.