Nicholas,
I think they basically boil down to being a cheaper alternative. I grew up in a rural area with no real access to a backpacking store. I could mail-order stuff from REI. Every year I'd get back a dividend on the amount of purchases, because the co-op ran itself more efficiently and wasn't chartered to make tons of profit.
>I didn't know they where so common.
>
>I liked Tamars example very much because it seems like a local group getting together which is quite (to me) appealing..