Quick answer
In KitForge FBT, add-on products appear as selectable recommendations on the trigger product page. Shoppers choose which add-ons to include; the bundle discount applies to selected add-ons (and sometimes the trigger) when added via the widget path.
- Add-ons are optional FBT complements on trigger PDPs.
- Discount applies when shoppers select add-ons via widget.
- Different from fixed kit components which are always included.
- hideUnavailableAddons keeps OOS add-ons off the widget.
Why add-ons are optional by design
FBT models real attach behavior — some shoppers want the hero only. Forcing components like a fixed kit would reduce conversion on the primary SKU. KitForge applies bundle discount only when add-ons are selected and added through the widget.
Curating add-on catalogs
3–5 relevant add-ons outperform long lists. Match accessory type to trigger — same scent family for candles, compatible fit for fashion, refill logic for consumables.
FBT discount not applying unless add-on is selected is expected behavior — not a bug.
Launch checklist
Apply what is an add-on product in shopify bundles when briefing your team so admin settings and storefront copy use the same language.
Confirm variant coverage, mobile layout, and that the discount only applies through the intended path so shoppers are not surprised at checkout.
- Preview the offer on a real product page and on mobile.
- Place a test order that exercises the discount and inventory path.
- Brief support on what is included and what is not.
- Document the success metric before you scale the offer.
Mistakes that quietly kill conversion
Mixing terms — kit, bundle, BOGO, free gift — creates wrong expectations for shoppers and for support.
For “What is an add-on product in Shopify bundles,” keep the page focused on one primary next step. Extra widgets, stacked badges, and unclear exclusions increase bounce more often than they increase AOV.
- Do not hide eligibility rules until checkout.
- Do not bundle unrelated leftovers without a customer story.
- Do not skip mobile QA on choice-heavy widgets.
- Do not launch without a rollback plan for the discount.
How to measure whether it worked
If the definition is clear, a new teammate can configure the offer without asking which Shopify surface owns the rule.
If the metric moves but support volume rises, fix presentation or inventory rules before cloning the offer across more SKUs.
- Attach rate on treated product pages
- AOV and contribution margin after discounts
- Refund or fulfillment exception rate
- Time for a teammate to edit the offer safely
Final recommendation
Add-on products are the selectable half of FBT — curate few relevant items, verify discount on selection, and distinguish them from fixed kit components.
If you want this kind of offer to feel native to the buying journey, Kitforge Bundles is built around that exact problem: turning related Shopify products into clearer bundle offers before the shopper reaches checkout.
FAQ
Can add-ons include the trigger product?
Typically no — add-ons complement the trigger. Duplicate SKUs confuse shoppers; use quantity breaks on the trigger for multi-unit instead.
What if all add-ons are out of stock?
With hideUnavailableAddons enabled, the FBT widget may show no add-ons or hide entirely depending on configuration. Restock or swap add-ons.
What should I do before publishing changes related to What is an add-on product in Shopify bundles?
Preview on mobile, place a test order, and confirm inventory and discount behavior match the storefront promise. Only then activate for all traffic.
When is Kitforge Bundles the wrong tool?
If you only need a simple Buy X Get Y or free-gift discount with no product-page merchandising, native Shopify discounts may be enough. Kitforge is built for fixed kits, FBT, and quantity-break widgets with inventory validation.
How long should I wait before judging the offer?
Give the offer at least one to two weeks of normal traffic, or enough orders to see attach rate stabilize. Seasonal spikes can distort a shorter window.