It's always a good idea to schedule "check-ups" after a sale is made. These meetings can be formal or informal, and can take place face-to-face or over the phone. Not only are these post-sale steps effective for providing service after the sale, they should be talked about in the pre-sale stages to help in the closing.
Scheduling "post-buy meetings" before the closing sends a clear signal to prospects that you're not going to run away and that a "partnership" is actually beginning. You may separate yourself from the competition by developing better strategies and processes for the after-sale process.
It's the best way to make sure the customer is happy with the product and to get feedback on ways you could improve.