This is a complete plain-English reference for the Amazon, Etsy, eBay, TikTok Shop, Shopify and broader ecommerce vocabulary you’ll encounter as a UK seller in 2026. Bookmark and share.
Amazon-Specific Terms
- ACOS
- Advertising Cost of Sale — ad spend divided by ad-attributed revenue. See benchmarks.
- A+ Content (formerly EBC)
- Enhanced product description with images and modules, available to Brand Registered sellers.
- ASIN
- Amazon Standard Identification Number — the unique 10-character ID for every product on Amazon.
- Brand Registry
- Amazon’s brand-protection programme. Required for A+ Content, Stores, and most brand tools. Brand Registry guide.
- BSR
- Best Sellers Rank — Amazon’s ranking of how well a product is selling within its category.
- Buy Box
- The featured offer shown when a buyer clicks “Add to Basket.” Multiple sellers can compete for the same Buy Box on identical products.
- FBA
- Fulfilled by Amazon — Amazon stores, picks, packs, and ships your products and handles customer service.
- FBM
- Fulfilled by Merchant — you store and ship products yourself.
- Long Tail Pro / Long Tail Keywords
- Specific multi-word search queries with lower volume but higher conversion intent.
- Negative Keyword
- A search term where you do NOT want your ad to show. Critical for ACOS control.
- PL (Private Label)
- Selling generic products under your own brand.
- Q4
- Quarter four (October–December) — the biggest sales window of the year.
- SKU
- Stock-Keeping Unit — your internal identifier for a product variant.
- Sponsored Products
- Amazon’s most basic ad type, showing single products in search and on product pages.
- Sponsored Brands
- Banner ads showing your brand logo and 3+ products. Brand Registry required. Sponsored Brands guide.
- Sponsored Display
- Display advertising on and off Amazon for retargeting and audience targeting.
- Search Term Report
- Report showing the actual queries that triggered your ads. The most valuable PPC report.
- TACOS
- Total Advertising Cost of Sale — ad spend divided by total sales (including organic). Better measure than ACOS for advertising efficiency.
- Variations / Parent-Child
- Linking related ASINs (sizes, colours) under a single parent listing.
- Vine
- Amazon’s reviewer programme. Brand Registered sellers can enrol products to receive reviews.
Etsy and Marketplace Terms
- Etsy Ads
- On-platform advertising on Etsy. Pay-per-click model.
- Offsite Ads
- Etsy ads run on Google, Facebook, etc. Etsy charges 12–15% commission on resulting sales.
- Star Seller
- Etsy’s seller-quality programme rewarding fast shipping, fast responses, and high reviews.
- Tags / Attributes
- Etsy’s metadata fields used for search ranking. Maximum 13 tags per listing.
TikTok Shop Terms
- Affiliate / Creator
- An external content creator earning commission for your sales.
- GMV
- Gross Merchandise Value — total sales value before fees and returns.
- Live Shopping
- Live-streamed sales events where viewers can buy products as creators demonstrate them.
- Open Plan vs Targeted Plan
- Two TikTok Shop affiliate models. Open lets any creator promote your products; Targeted requires creator approval.
Shopify and DTC Terms
- AOV
- Average Order Value — revenue divided by number of orders.
- CAC
- Customer Acquisition Cost — marketing spend divided by new customers acquired.
- CLV / LTV
- Customer Lifetime Value — total revenue from a customer over their relationship with your brand.
- CR / Conversion Rate
- Percentage of visitors who buy. Standard ecommerce CR is 1.5–3%.
- DTC
- Direct to Consumer — selling directly via your own site rather than via a marketplace.
- ROAS
- Return on Ad Spend — revenue divided by ad spend. The inverse of ACOS for non-Amazon contexts. ROAS of 4 means £4 revenue per £1 spent.
- Shopify Plus
- Shopify’s enterprise tier. Significantly more expensive than standard Shopify.
Sourcing and Operations Terms
- 3PL
- Third-Party Logistics — an external warehouse handling fulfilment.
- FCL / LCL
- Full Container Load / Less than Container Load — shipping container terminology.
- FOB
- Free on Board — the supplier loads the goods onto the ship; you take responsibility from there.
- HS Code
- Harmonised System code — the international product classification used for customs.
- Lead Time
- Time from placing an order with a supplier to receiving the goods.
- MOQ
- Minimum Order Quantity — the smallest order a supplier will accept.
- SKU Velocity
- How quickly a SKU sells through inventory. Drives reorder timing.
Marketing and Analytics Terms
- Attribution
- Identifying which marketing touchpoint led to a sale. Increasingly difficult in 2026 due to privacy changes.
- CTR
- Click-Through Rate — percentage of impressions that turn into clicks.
- CPC
- Cost Per Click — what you pay each time someone clicks your ad.
- CPM
- Cost Per Mille — cost per thousand impressions.
- Funnel
- The journey from awareness to consideration to purchase.
- iOS 14 / ATT
- App Tracking Transparency — the privacy change that disrupted Facebook ad attribution from 2021 onwards.
- Pixel
- The tracking code that ad platforms use to record conversions on your site.
Need Help Translating Theory to Practice?
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