One product, many variants
Group existing products as variants of one product, render a picker, and resolve variants from backend scripts.
You sold one supplement in a 1, 3 and 6 pack as three separate products, and every storefront needed three buttons and a paragraph explaining the difference.
The enemy is three products that are really one product.
A product can now group existing products as its variants. Each variant keeps its own code, price and SKU, so carts, fulfillment, payouts and postbacks work as before. Storefront pages get the options and variants with the product to render a picker, and backend scripts can call resolveVariant(). Pick the product for a variant from a list instead of typing its code.
Try it: open a product, add two existing products as variants, and render the picker on a product page.
Documentation