You know, it is ok to, w/o putting anyone down, tell them about dog foods that don't cost more, but are much better for their dog, and more nutrition for their money.
I generally feed Nature's Recipe, or Nutro Natural Choice, or Ultra, but the last couple months, I have fed PetSmart's own brand [I visited there by chance, a salesman pointed it out to me] Authority.
I am feeding the pink bag puppy kibble [there are 2 puppy kibbles, the other one is crap].
It is close to $20. for #40 lbs. I paid $23. last week, but it goes on sale for less.
I still will go to Petco, and add the other brands into their diet. I get a free bag every 10 I buy there, it drops the average price. [I use 10 bags in 2 months].
Offer an alternative, and don't just dis' people for what they do.
Even if they don't respond at the time, or are startled, they will remember what you had to say. Their pride will let them see things your way, if it is within their means.

Walmart isn't that bad.....LOL!!!! Actually I have to go buy a few grocerys today and I am going to a different grocery store. Pretty bad I can barely stand to shop in the store I work in.

Those were good articles.
I pretty much had all that info introduced to me in my 3rd year of college, in Beef Production class, 20 years ago,we got to see the making of pet food a-z...
As to Nature's Recipethe incident the article referred to was MANY years ago, and before they were bought by Heinz. I was in contact with the company that made it at the time...certainly the incident was unsettling, but Nature's Recipe was the ONLY company with the guts to recall the products. SEVERAL national brands of dog food had bought that spoiled grain [it all came from the same farm, it was not a problem that spread beyond the sale of that one infected lot of grain]. The other companies left their products on the shelves. Nature's Recipe risked their reputation for all time, by being too ethical not to recall the product.
Not saying that Heinz has done the product any favors, [they switched the brown rice to white], but I was assured at the time by a once management employee of NR, that Heinz payed way too much money to acquire NR, to risk screwing it up. I remain happy with the results I get from it. It does have to be fresh though. You must check the bag dates...