Make repeat purchases effortless. Buy it again shows each logged-in customer what they bought before, with today's price and stock and the option they chose (size, colour), and adds it to their cart in one tap. Customers who order the same things again and again can reorder a whole past order at once.
Nothing is added blindly. Every item is checked against your catalog when the customer taps: sold-out items, deleted products and options you no longer offer are skipped, and the customer is told exactly what was left out and why. If a price has changed since their last order, they see both prices.
Put the widget on your My account page or any members page, and on the thank-you page so the next order is one tap away. Customers always check out the normal way, with your shipping rules and today's prices.
Customers only ever see their own orders: who they are comes from their login, never from the page. Your dashboard shows how often customers reorder, which products they add again, and the sales that followed a tap. Flat monthly price, no share of your sales.