PETCO at least directs people to adopt an animal if they're purchasing a dog or a cat (just like superpet here in canada).
I know the chains have their issues but they're better then they used to be. and they can only do that with our support, both as suppliers and customers.
as for what peta wants us to do with our animals... i can just immagine the terror they'ed be in if we set them all free, my dog would definetly starve, he's lucky to catch grass.
I'd also rather support some one who's on our side (petco) then some one who's out to get us (peta).
I know superpet deals with local breeders for some of their small animals (I know because i sell them live rats for PETS only). Thats community support... What peta wants to do is destroy your community and make it a sterile and unfriendly place.
I like my version of peta better... People for the eating of tasty animals.