A great many people base their business strategy on prices. They proclaim that theirs is the lowest price. That is a strategy of limited appeal. Not every one is looking for the lowest prices. A surprisingly large number of people prize convenience above low price.
People like to be recognized.
With today's computers, it's easy to send a thank you note to a new buyer, along with the merchandise, addressed to that new buyer by name. Start a database, and keep a record of what each buyer has bought. Send each one a postcard, along with some sales literature, a few days after filling the order. They will be astonished and pleased. So many businesses simply take their customers for granted.