Boring Conversation Starters
Ever notice how someone asks, "How are you?" but they don't really care about the reply, and then you still feel obligated to ask the question in return? It's a weird formality that people say when they start a conversation but just leads to pointless banter. Americans are really great at this.
Cashier Small Talk
Most people like self-checkout so they can avoid cashier small talk. The panicked "hey this juice is really great," kind of conversation is just the product of feeling awkward and pressed for time while scanning your items. In reality, cashiers aren't exactly thrilled to be there either.