Liz Handlin has a great post up about the chutzpah of people who take advantage of the time and expertise of people in their network (or even people not in their network) and don't bother to express any sort of appreciation.
This resonated with me because of some irritating experiences I've had lately. Here's the thing: I do this blog for free, on my own time, because (a) I have an apparently pathological need to share my opinion, and (b) it's incredibly gratifying to help people figure out how to navigate the sorts of sticky situations we talk about here. Sometimes people write back to thank me for the help, or to let me know how their situation turned out, and I love love love that. It feels awesome.
Here is what does not feel awesome: When I spend the time to send someone a private response not intended for publication (sometimes an immediate one, because their situation is time-sensitive), or when I spend not insignificant time giving them feedback on their resume or cover letter, and I hear ... nothing in response. Literally nothing. It's rude. And it's bizarrely common. (And it is not smart; I will go way out of my way for you if you express appreciation, so you should at least be machiavellian about it, if for no other reason.)
So go read Liz's rant and make sure you are never, ever doing the sort of thing she describes.