A response, action on the request, may be almost instantaneous (I reported a wildly out of control, all kinds of personal attacks thread about a week ago, closed in 5 minutes) to ignored.
I have thought it good basic courtesy, if not also good business sense, to reply to a poster who has taken both the interest, concern and time to report a post/thread/inquiry to the moderators. When a post is reported, that report is emailed to all the moderators of that particular board, all the webmasters (and I'm not sure about the 'super moderators').
I would think that the reporting poster should be replied back to, with an indication of either 'we dealt with it or it was judged to be fine' and a 'thank you for your concern' by one of the above, whoever chose to deal with it, with a cc to the others in receipt of it, informing them of it being acted on, one way or another.
My experience of late is that I do not (I retract, when I have sent direct to Pete, he has replied me) get a reply back on a 'report to moderator'. I sometimes check back to see if action was taken, sometimes it has, sometimes nothing. If is is really a point of contention with me, and nothing done, I will resend. A few weeks ago, I resent one 3 or 4 times, finally acted on.
So, you just never know, TL.
As for...
....Depending on what you are reporting, it may or may not be looked into, or it may not be as urgent to the mods as it is to the reporter....
I think ANY report to a moderator should be looked in to as well as replied back to the reporting poster, JMO. And yes, a lousy job to do for free, however, basic responsibilities and courtesies go with it. Again, JMO.
Dan