Which of the following is not an example of a direct network effect? An increase in the number of buyers on Amazon Marketplace makes it a better platform for potential sellers and increases options for buyers. An increase in Yelp users prompts restaurants to improve, in turn helping other Yelp users get a better dining experience. An increase in the number of users of WhatsApp provides more potential contacts for WhatsApp users. An increase in the number of Xbox users increases the number of potential game partners or competitors