The pre-sale is the time before a customer decides to buy your product or service. In this time, you have the opportunity to make a great first impression with your product and to help them see why they should purchase from you. The post-sale is when customers have already bought your product or service. This is the time for you to make sure that they are satisfied with their purchase and that you are able to follow up on any questions or concerns that they might have. Pre-sales are important because it gives you an opportunity to build trust with your potential customers. If done well, it can help ensure that they turn into loyal buyers who will continue buying from you in the future.