I don't think they are chain, Goodwill has become a chain store IMHO, they all look the same. From what I understand the Re-store support the Habitat for Humanity mission (I do too), the proceeds from local stores feed the local mission. However Goodwill and Habitat 4 Humanity both have a 4 star rating with Charity Navigator, they don't rate Salvation Army.

I also agree with Rowan that the pricing in many of them has become a bit exorbitant. We volunteer to work at a thrift store that is run by a church that we attend. I help with the pricing, the money raised goes to a variety of missions, ranging from the local soup kitchen to overseas missions. Things like clothing and kitchen items are priced very low, we usually try to price "collectible" items a bit higher to avoid the people that are looking to make a quick buck on something. We are in the process of setting up an eBay store to help sell some of the more unusual items. One recent donation that has us scratching our heads on the best way to sell it fairly is a complete set of fine china, crystal and sterling silver. Definitely not normal thrift store items. One major issue for many thrift store operations is people will bring in stuff that should have gone to the dump. My criteria has always been, if it isn't good enough for me to wear it isn't good enough for the thrift store. It is a hard judgement call though, everybody has different standards.

Aaron