An example of deontological thinking that I think is very common occurs when sales people interact with customers. Although a salesperson might want to maximize their utility by recommending customers products and services they do not need, it is looked down upon by society. The reason for this is deontological thinking is deeply ingrained in us to realize that the salesperson has a duty not to misinform a customer. That it is immoral to take advantage of someone lack of knowledge. This duty supersedes the seller’s incentive to maximize their own utility by trying to maximize the profit on each individual sale.