Facebook Ads often fail to convert due to improper targeting, and one solution is to use Facebook Custom Audiences, which leverages existing customer data to identify potential buyers more effectively. By integrating tools like Facebook Pixel or services like Datagran with a Shopify store, advertisers can create Custom Audiences based on website visitors, customer lists, and shopping patterns. This approach not only helps retarget visitors who did not make a purchase but also aids in creating Lookalike Audiences to reach new customers similar to existing ones. The process involves setting up a Facebook Business account, using tools to collect and analyze customer data, and creating targeted ad campaigns that potentially increase conversion rates. Datagran facilitates this by connecting Shopify data to Facebook Ads, allowing businesses to enhance their targeting strategies and optimize ad performance.