Getting customers through the door is just the beginning, says this article from Experience Retail Today. The real challenge is getting them to buy something. To address this challenge, you have to think in terms of retail assortment: the number and types of products you stock.
It seems a fairly straightforward problem, but to get it right, you have to know your customers and why they choose you. Businesses known for their low prices might stock a very wide, but not very deep, assortment. But a more specialist niche might offer a very deep assortment of only a few different products. You also have to think in terms of related products: an ice cream shop, the article points out, might offer frozen yogurt or cookies to those looking for a dessert other than ice cream.
The full article provides more detail on retail assortment strategies, including different types of strategies and which strategies work for which types of business.