So, in the big ol' world, outside of the folks I normally hang with, there's a standard bit of conventional wisdom that goes, "after a date, a guy should wait a day or a couple of days to call back, so he doesn't seem too eager." If he waits longer than about a week, it usually means he's not going to be calling back.
Our little community tends to regard this as passive-aggressive... It's important to call back, or otherwise communicate, soon and preferably with "let's do this again" or some suitable "um, it was fun, but I think I'm busy for awhile" sort of rejection. We're also not as strongly gendered about who communicates first. Communicating quickly can solve a lot of scheduling issues, and (for instance) successful polyfolk have so many scheduling issues that most date-related polyfolk-specific ritual revolves around reducing the scheduling headache.
However, in the less-scheduling-obsessed world that surrounds them/us/whatever, rituals often have other purposes. And the interesting thing about the timing of calling back is that the person calling back gets to choose the light they are seen in. If the date ended poorly, you're better off waiting longer to call because the other person has had more of a chance to forget the specifics of your loser-dom and (with luck) remember mostly that you were polite and nice and have a productive job :-) Stuff like "spinach between your teeth" usually fades from memory faster.
I hadn't even considered that. It's really a kinda neat idea. I'm not planning to pick up such habits, what with me being all monogamously married, but it's still a good thing to keep in mind when giving advice or hearing it. 'Cause that does make a difference in people's reactions.