I haven't read this entire thread, so this point may have already been made.
This is not meant as an argument to support "false adoptions". Pet stores that claim "adoptions" when there is no adoption organization involved, or when the animal was not surrendered by a previous owner, are just lying. I think one previous poster identified himself as a pet store employee, and categorized "sick breeder mill animals unfit for sale" as "adoptions". A bit of a self-incriminating statement. An animal bred for sale is not an "adoption", even if it is sick and the pet store wishes to punt on the cost of treating it. In addition, I don't know any rescue that would adopt out a known-to-be sick animal.
In regards to the thread subject:
Adoption organizations that choose to hold adoption days at pet-selling pet stores do so because that is where every day people go when they are looking for a pet. If the adoption agency was not there, those people are most likely going to buy a pet from the pet store.
An adoption day at such a location is an opportunity to intervene, and educate consumers on the benefits of animal adoption. If the consumer is at the pet store, and considering purchasing a pet, this means that the consumer is probably unaware of the mals behind the scenes. The adoption agency will provide the customer with an immediate option to adopt rather than purchase. More importantly, the information given out by the adoption agency will provide pointers to articles describing the real state of affairs at pet stores. The customers may then educate themselves, and may even talk to their friends and family about it. The customer will also learn what it really means to get a rodent, and may chose otherwise.
This is the very reason that some pet stores don't allow adoption organizations in their stores. They don't want their customers to learn what is going on behind the scenes with their animals. The beginning of this thread talked about a pet store chain which either banished adoption agencies from their locations, or made sure that they were positioned in a way so that they had no real access to the customers. Do you think they are really concerned with missing out on a $30 guinea pig sale, when bags of the bedding cost $25. Do you think they make a lot of money selling $8 hamsters? No. They did not want the adoption organizations providing information to their customers. They don't want customers thinking about the realities and responsibilities of becoming a rodent owner. They want the customer to see how cute they are and spontaneously buy one, so that they can then get on with buying a cage, bedding, bottles, litter boxes, hay, feed, toys, etc.
I understand the point of not wanting to "support the pet store in any way", but I'd argue that forfeiting the opportunity to get direct access to a pet store's customers is supporting them. These customers are not out educating themselves about the need for animal adoption, and the pet store most certainly is not going to inform them. These pet stores are going to continue to do business without check, selling sick and abused animals to the unknowing public, who don't know what they are getting into by getting a rodent.
Granted, there are many means by which the general public can be informed on this issue, such as news media and the Internet. I can see how some organizations might think that the pet store floor is a good one as well.
To frame it another way, what would be the effect if every petsmart and petco in the nation provided genuine store space to the rodent rescue organizations in their area, and access to their customers. Would this improve or retard the overall state of rodent welfare, even if they still sold mill animals as well.
Mill animals are not going to be dealt with by going around and telling people "shame shame" for shopping at a pet stores. I'd advise creating a regulated term, such as "organic" did with food. Come up with something snappy, like "healthy bred". Start breeding in a responsible way. Sell your "healthy bred" pets to responsible pet stores. When somebody asks, "what does healthy bred" mean, you can say, well, they were not raised in a pile of sh!t, like any animal not labeled as "healthy bred" is. Guarantee the health of "healthy bred" animals by taking them back if they are sick for treatment. Imagine that. A breeder that takes back animals. Require that any pet store selling Healthy Bred animals also provide adequate access to local rescue organizations to place adoptions with their customers.
Have a catch phrase: "If it's not 'healthy bred', you might as well have pulled your pet rodent up out of the sewer."