If you're creating an affiliate marketing store to send customers to external marketplaces for their purchases, using these apps is the quickest way to get up and running. These apps are also great for store owners who want to give their customers the option to buy on external marketplaces instead of directly through their Shopify store. With external links "buy now button," your customers can choose from multiple options to purchase from, which can increase your conversions and allow you to track which platforms your buyers prefer. Most of these apps also allow you to create custom buy now buttons that match the style of your store.