It might seem obvious that you should sell people what they want. However, the problem arises when they might want one thing yet need something else. If you sell them what they want but not what they need, they will end up dissatisfied and telling them afterward “it’s not my fault, that is what you wanted” wont do you much good when it comes to repeat customers/sales
Instead, sell them what they want but also give them what they need. Think of it as a bonus. They leave happy short term because they got what they wanted and long term they will be happy because they also received what they needed.
Sometimes you have to be sneaky (think of it as providing a bonus) but long term, it will be best for all concerned
Have a great day!