Final answer:
The foot-in-the-door technique involves starting with a minor request to build compliance and eventually leading the customer to agree to larger requests, as seen in scenarios like purchasing a new smartphone and being persuaded to add a premium data plan and then an extended warranty.
Step-by-step explanation:
The foot-in-the-door technique is a sales strategy where a salesperson starts with a small request to gain the initial commitment of a potential customer, with the hopes of leading them to agree to larger requests. In the scenario of purchasing a new smartphone, a store owner might first persuade a customer to buy a premium data plan, before suggesting a more costly addition like a three-year extended warranty.
The idea is that agreeing to the smaller initial request increases the likelihood of a customer agreeing to bigger, more expensive options later on. This complies with the principles of conformity, compliance, and obedience, where a person's likelihood of saying 'yes' is influenced by their prior actions and the perceived authority of the salesperson.