Shopping Carts
The checkout experience — cart functionality, abandonment, and what affects conversion.
What a Shopping Cart Actually Does
A shopping cart seems simple but involves multiple moving pieces working together. It's not just storing items—it's managing session state, handling inventory conflicts, calculating prices dynamically, and guiding users through a conversion funnel.
The cart must survive page reloads, browser closures, and device switching. This requires persistent storage (database or local storage sync). Customers expect their cart to be there hours or days later.
What happens if someone adds 5 items when only 3 are in stock? Real-time inventory checking prevents overselling. Complex with multi-warehouse scenarios.
Total price isn't just items × price. It includes discounts, bulk pricing, tier-based pricing, tax, shipping, and promotional rules. Rules must evaluate in the right order.
Customers change quantities, remove items, apply coupon codes. The cart recalculates everything instantly. For some products (pre-orders, limited editions), quantities have minimum and maximum bounds.
The cart is a conversion point. Suggesting related products, bundles, or upgraded options can increase AOV by 20-30%.
The Cart Abandonment Crisis
Approximately 70% of shopping carts are abandoned before checkout completes. That's $18 billion in lost U.S. e-commerce revenue annually. The cart is where people decide whether your business is worth their time and money.
- Unexpected shipping costs (revealed at checkout, not earlier)
- Forced account creation before checkout
- Too many form fields in checkout
- Security concerns (unfamiliar payment processor)
- Unclear policies (returns, warranties, support)
- Technical errors or slowness
- Comparison shopping (customers are checking competitors)
Cart Abandonment Emails
Sending a reminder email to customers who abandoned their cart recovers 5-15% of abandoned revenue. But this requires:
- Capturing email address before abandonment
- Tracking which products were in the abandoned cart
- Sending triggered email at right time (1-3 hours later)
- Making the email personal and compelling
- Offering incentive or reassurance (free shipping, guarantee, discount)
- Managing unsubscribe and compliance
Checkout Flow Design
Every step in checkout increases the chance of abandonment. The goal is minimum friction while capturing necessary information.
Single-page checkout loads faster and feels simpler. Multi-step checkout allows you to ask questions progressively (shipping before payment), reducing cognitive load. Research suggests mobile prefers single-page, desktop prefers multi-step.
Guest checkout converts higher first-time. User accounts help with repeat purchases and customer data. Solution: Guest by default, optional account signup after checkout (you already have their email for login recovery).
Surprises kill conversion. Show estimated shipping costs at cart, before checkout. Show tax before payment step. Never hide fees until the final confirmation.
Customers have preferences. Credit card is still primary but Apple Pay, Google Pay, and PayPal are essential. Missing a payment method your customer expects causes abandonment.
Buy Now Pay Later (BNPL) Options
BNPL (Klarna, Afterpay, Affirm, Sezzle) is increasingly important for checkout conversion, especially for higher-priced items. Younger customers specifically look for these options.
Allows 4 interest-free payments. Popular in Europe and Australia. Growing in U.S.
4 equal payments, 2 weeks apart. Popular with fashion and smaller ticket items.
Flexible payment plans. Offers interest-free and interest-bearing options. Popular for furniture and higher-priced items.
4 equal payments. Targets Gen Z. Lower approval thresholds than competitors.
Most BNPL services charge the merchant 2-8% of transaction value. They handle the consumer credit risk, so you get paid upfront. Adding BNPL options can increase conversion 10-30% for qualifying products.
Cart Capabilities by Platform
| Platform | Guest Checkout | Cart Abandonment Email | Custom Fields | BNPL Support |
|---|---|---|---|---|
| Wix | Yes | Limited | Limited | No |
| Squarespace | Yes | Limited | Limited | No |
| WooCommerce | Yes (custom) | With plugins | Full control | With plugins |
| Shopify | Yes | Native | Limited | Native (Klarna) |
| Custom | Full control | Build yourself | Full control | Integrate any |