For brick-and-mortar retailers adding e-commerce, the top three options are: Shopify ($29-79/month, best for dedicated e-commerce with robust shipping tools), Square Online (free to $79/month, best if you already use Square POS for seamless inventory sync), and WooCommerce (free plugin on WordPress, best if you have technical support and want full control). The right choice depends on your POS system, technical comfort, and the volume of online orders you expect.

The biggest operational headache for brick-and-mortar e-commerce is inventory sync — a product sold in-store should immediately show as sold online too. Square POS syncs natively with Square Online; Shopify has its own POS app; Lightspeed integrates with most platforms. If your POS does not sync with your e-commerce platform, you will need to manually update inventory, which leads to overselling and frustrated customers.

Not every product in your store translates well to online sales — fragile, heavy, or highly customized items may cost more to ship than they are worth. Start with your 20 best-selling, highest-margin products that are easy to photograph and ship. Reserve rare, expensive, or service-intensive items for in-store purchase where your staff can add value through guidance and personalization.

Online sales have additional costs that in-store sales do not: platform fees (1-3% per transaction), payment processing (2.9% + $0.30), shipping materials, and potentially shipping labor. Calculate your online profit margin per product before listing: a $20 item with $5 cost of goods might only yield $6-8 profit after platform fees, shipping materials, and transaction fees — still worth it, but know your numbers.