I have vivid memories of my thirteen year-old self sprawled on the living room carpet--long, lanky legs, limp perm, retainer--grumpily eyeing two piles in front of me. The first was a colorful assortment of envelopes, fancily-wrapped boxes, and ribbony gift bags; the second, a neat stack of notecards in my theme colors, peach and turquoise (hey, it was 1989).
The rule was that thank you notes had to be written as I opened my presents. And so with each check or bond or engraved Cross™ pen and pencil set that I opened, I dejectedly pulled another card off the pile, and began scribbling.
"Dear relative I probably haven't met,
I'm so glad you came to my Bat Mitzvah. It was nice to see you. I hope you had fun. Thank you so much for your generous check/bond/Cross™ pen and pencil set. I'm sure I will put it to good use.
Gosh, but I was an ungrateful, miserable, young woman*. I hated writing thank you notes then, and I hate writing them now only slightly less, but alas, they are a part of basic etiquette--especially when you've been on faculty interviews.
Have you just returned from an interview? Congrats! I'm sure you rocked their world. To rock their world further, I'd recommend waiting no more than 3-5 days to send a few thank you's out. The chair and your host, for sure, and maybe if there's anyone you especially enjoyed talking to. I do not think these need to be actual paper snail-mail cards, but use your judgment--if you met someone you think would particularly appreciate a little old school gesture, by all means go right ahead and dig out a stamp. Personally, I think email is fine, and perhaps even preferable for its guaranteeable-ness and instantaneousness. Who knows what gets lost in the bowels of a research institution's mailroom, you know? Certainly several of my rejection letters.
But what do you say in a thank you note? That doesn't make you sound like a robot? Well. To put it succinctly, say things that are nice, and also specific. And try your best to be genuine! Don't be post-Bat Mitzvah Becca**. What did you *really* like about the department? Did you find that there was a happy, community-like feeling? Say that! Did you have fun with the students (so far, this has been one of the highlights of both my interviews)? Say that too--even research-heavy programs want you to care about the students, and not just be all give me my sweet-ass lab, bitches! If you're writing to someone you could see as a future collaborator, say something about how well your research interests jive, and again, be specific! The more personal these notes are, the better they will like you and the more they will see you as a potentially awesome colleague. Which is, if I'm not mistaken, the goal here, no?
*according to Jewish law
**You could instead, of course, always just quote Wayne Newton, although the decision to call the department chair "Darling" should be handled on a case-by-case basis.