Claus Lauter made a fantastic point on Ecommerce Coffee Break that shifts the focus from a generic benchmark. He described auditing a store with a great add-to-cart rate but a very, very low checkout conversion rate. The culprit wasn't button colors or a missing progress bar; it was that the store offered only standard credit card payments to a market where other payment methods were far more common and trusted. This gets to the heart of the matter. A 'good' checkout completion rate is one that's designed for your specific customer, not one that hits an arbitrary number.
This is where being on Shopify Plus becomes a real advantage. While a standard Shopify store's overall conversion rate is often a sobering 1.4% to 1.8%, as Philip Jackson mentioned on Shopify1Percent, Plus gives you the tools to meaningfully improve that. The conversation stops being about a single benchmark and starts being about what you can build. Kyle Truong pointed out on Ecommerce Coffee Break that with checkout extensibility, you're no longer stuck with a rigid, three-step process. You can customize the checkout to answer last-minute questions, add trust-building reviews directly to the page, or offer upsells in a way that feels helpful, not disruptive. This ability to modify the checkout is the key differentiator for Plus merchants.
Instead of searching for a single number, I'd think about it in terms of a baseline and the lift you can get from specific actions. For instance, Kunle Campbell noted on the 2X eCommerce Podcast that Shopify's own data shows Shop Pay can increase conversions by 18% for returning customers. That's a concrete improvement from a single feature. Your job on Shopify Plus is to stack those kinds of improvements. Start by ensuring you have the right payment mix for your geography, as Claus suggested. Then explore what checkout extensibility can do for you. Can you add a testimonial? A link to a sizing guide? A last-minute shipping reassurance? The benchmark becomes your own store's performance last month, and the goal is to find the unique combination of features that continuously pushes that number higher.