I don't think there is a magic number, I have had days with a huge number of clicks and either low or no sales. Other days I have had just the opposite. It's the quality of the traffic, not the amount, that makes us money.
Same here; I've had a big increase in number of clicks in the last week or two, but very low sales. Last month I had at least 2 instances of someone who bought a large number of things for pretty good money form eBay, and fortunately for me they'd passed thru a website of mine and dropped the cookie. So from those 2 or so clicks, I got a very good amount of money (maybe $100-$200). Lately I've been getting around 150-200 clicks a day, but commissions have been terrible.