Says the bagman.
They are usually bundled as "rags"and sold (fairly cheaply) to industry.
AFAIK they are sorted, which means if you're a regular op-shopper - beware, you might be buying back that cool Star Wars embossed t-shirt that only fitted you 15 years ago.
(Misery McUglywife an attention seeking sociopathic fuckstain., Tue 28 Feb 2012, 9:13, 1 reply)

Again, based on heresay
these are not old rags, they're asking for good quality clean stuff.

It gets exported to places like Nigeria, and sold there. Not as rags.

They don't just ask for clothes. It's toys, shoes, small electrical appliances.

I could be completely wrong, but it sounds more than feasible.
(username failed moderation, Tue 28 Feb 2012, 9:37, closed)

Furry muff.
I think what I suggested happens here in Oz. I don't have any "inside knowledge".
So yeah - based on hearsay.
But having worked in a couple of places that bought rags off charities, rest assured that some pimply-faced teenager wont be buying your favorite Dr. Who t-shirt just 'cause it's cool.
EDIT: Over here it's illegal for then to accept *any* electrical goods - they can't test and tag them so they cannot sell them as safe. Even in Nigeria!
(Misery McUglywife an attention seeking sociopathic fuckstain., Tue 28 Feb 2012, 10:42, closed)