Perhaps: * Take the first 90 results. * Send the email, wait some specified time (Perhaps 75th percentile of time of how long it took to get the first 90 resu

Perhaps: * Take the first 90 results. * Send the email, wait some specified time (Perhaps 75th percentile of time of how long it took to get the first 90 results) * Apply Bayes Theorem if there are new replies and move on. Alternatively, having someone go physically TALK to students in quads and cafeterias will probably generate a higher quality of data. I'm guilty of it myself, but sometimes after a negative experience, I'm apt to just leave a 1-star review when it should really be a 3 or 4, out of spite. I think the internet has the inhibition-removing quality that encourages these behaviors, whereas if someone outside the store or whatever just asked me "Hey, how was your experience?" I'd have probably said, "Oh, it was alright, just wish they'd had the sauce I always order, I had to get something different." But anyhow. It's probably C.