"I have a bridesmaid dress that I would like to donate to either a Youth organization or someone in need. It is a size 14, spaghetti straps, lavender in color, has a wrap and worn once. I will send photos if interested. I would like to donate the dress to a good cause so please do not respond otherwise."
This is a common free section conceit – the “to a good cause” model. People who not only want to unload their crap, but want to someone to say “thank you” for it, preferably on official letterhead. Whenever I see these, I think of one of the DSM's criteria for narcissistic personality disorder - "requires excessive admiration." I get the feeling some of them imagine that a wing of the organization’s headquarters might one day be named after them, in honor of their generous donations.
Let’s take a moment to understand the worldview of the poster of this listing. She believes that “good causes” are scouring the free section of Craigslist looking for bridesmaid dresses. She also believes that once they find her listing, they will do whatever it takes to take possession of the dress: e-mail her, perhaps trade a photo or two, arrange for a meeting, drive there (bringing along, of course, notarized copies of their non-profit articles of incorporation and tax ID number). All for the prize of her used bridesmaid dress. Maybe that's delusional rather than narcissistic. But no one says you can't have both!