another thing is the type of store. chain stores have a one-size-fits-all mentality, while independent stores usually have the ability and the inclination to keep hard to sell or large fish in larger, less crowded tanks.
although i'm all for customer education, listing things like "this fish will get up to 10 inches and therefore should only be kept in a 5000000 gallon tank" are kind of like selling a packet of tomato seeds stating that it requires 5000000 acres of land as it will eventually fill that in.
I've definately seen a difference with the major chains and the smaller stores in terms of the size of tanks and number of fish.
I have a huge opposition to doing business with anyone who sells puppies so that limits my choices in my area. I do have a good aquarium shop about 45 minutes away. It's the closest. We have a Petco closer that I stopped in on recently and was told they have a 14 day guarantee on all fish. That surprised me. Too bad I didn't get the bad advice from them to add Bio-Spira and 4 neons on the same day and everything would be "ok". Against my better judgement, I took the advice. The tank went into a cycle, ammonia and nitrites got high, I couldn't keep up with water changes and the neons died. (being brand new to this, I didn't know water could change that fast, that I needed to test that frequently and do daily water changes in necessary.) I was not a happy camper and I won't ever follow advice that is against my inner sense again. This plan of action came from a reputable lfs too. Maybe the Bio-Spira was not viable. That's my guess though it was refrigerated.
I've learned so much from you guys!