I just gave away 4 bags of fabric on Freecycle today... I was decluttering my sewing niche (long overdue) and had heaps of scraps, including some fairly big pieces (1-2 metres) and some small but nice bits of quilting cottons. I got four responses within about 5 minutes, then hastily posted a "Taken" to avoid more!
Our group's not too bad, partly because the concept of Freecycle hasn't caught on to mainstream NZ, so it's not a huge list. The moderators do occasionally have to send emails reminding people not to ask for absurdly expensive items, though ("Wanted: Fridge/freezer and washing machine"), and suggesting that it's rude to ask and ask without ever offering anything.
I've scored a few good items - two packets of brand-new fancyish darts, right when DH was saying he needed some new ones; and some nice big ceramic pots for the garden. I try to be polite and indicate a willingness to pick things up promptly. I don't always get what I want, but that's OK!
What annoys me a bit is when a big item is offered without any description. I know it's not Ebay, but how many people are going to want "a couch"? Just "a couch", with no indication of colour or size or condition? I certainly don't want to go all the way across town, hire a trailer, etc, to get some cigarette-smelling maggot-ridden 70s couch in mustard yellow with ripped seat cushions... you know? I've always wondered if those offers get any responses at all. So I try to be specific when I offer items (like, with the fabric, I mentioned the kinds of fabric, the range of sizes of the pieces, and so on - just enough to indicate that I wasn't getting rid of 4 bags of red burlap, or 4 bags of uncut lengths of French silk either!).