Typically applies to shelf-stable snacks, deli items, and beverages. Frozen foods and items requiring cooking are generally excluded. Pros
If your local store is hesitant about opening a product on the floor, remember that . You can buy any product, try it at home, and bring it back (even without a receipt in most cases) for a full refund if you aren't a fan.
Sampling a single bite in-store can prevent you from buying a full bag and tossing it later if you don't like it. Cons
It eliminates the fear of wasting money on a unique or "weird" new snack that might not suit your taste.