Only in the rarest of cases is a contract signed by both parties. In most cases, contracts just happen with both sides agreeing. The customer puts a few dollars on the tray, and the newsagent hands over the newspaper - a contract entered and fulfilled.
However, sometimes, customers probably do not even know the contractual relationships behind the services they purchase. They call an Uber through the app, the driver arrives, takes them from A to B and the customer is happy.
