What Are Related Products? Swaps vs Add-Ons

Swaps and Add-Ons Do Different Jobs

A similar item is a swap. It takes the place of the product on screen. That can save a sale you were about to lose, but you're trading one price for another, not adding a second item.

An item that goes with the product is an add-on. It joins the first item in the cart, so the order grows. Shown this way, an add-on is a cross-sell suggestion. A swap isn't one, since the shopper buys one item instead of the other.

Which kind helps depends on who's looking. A shopper who isn't sure about this product needs other options. Once they've decided, they need the piece that completes it.

Related products are one type of product recommendations. That's the wider term for any "you might like this" block, such as best sellers or recently viewed items.

Where Related Products Show Up on Shopify

Many Shopify themes, Dawn included, have a Related products section on the product page. Shopify fills it automatically from your store's data. Items that go with the product are a separate type, called complementary products. You pick those in Shopify's free Search & Discovery app, and it also lets you add your own related picks.

Across 958 Shopify stores in our visitor data, 6.72% of product views led to an add to cart. That means about 93 in 100 didn't. A related row gives those shoppers another option on the same page.

For the add-on side, our app Growth Suite has Frequently Bought Together and Product Add-Ons. With Product Add-Ons, you choose which items get paired with each product.

Example: One Shirt, Two Shoppers

A shop sells a $60 linen shirt. Its related row shows a $55 slim-fit shirt, a $65 heavier linen shirt and a $25 belt.

Shopper A thinks the $60 shirt is too loose, so she buys the $55 slim fit instead. Her order comes in $5 under the shirt she came for.
Shopper B likes the shirt and throws in the belt. That's an $85 order, $25 more than the shirt alone.

Both clicked the same row, but she made a swap and he made an add-on.

Our guide to related products and recommendations on Shopify covers setup and how to choose what shows.

Myth: A Related Row Always Makes Orders Bigger

Shopper A shows why not. If she was about to leave, the row kept the sale. It just shows up as a smaller order, not a bigger one. So don't judge the row by clicks. Use revenue per visitor, which counts kept sales and bigger orders alike.