Online Shopping Terms: E-Commerce Glossary for Beginners and Pros

E-commerce has a language problem. The industry runs on acronyms, borrowed marketing terms, and platform-specific jargon that can make even simple concepts feel opaque. This glossary covers the online shopping terms you'll encounter most often — whether you're setting up your first Shopify store, evaluating a new channel, or just trying to keep up in a meeting.

We've organized the terms by category so you can jump to what's relevant, or scroll through the full list alphabetically if you're looking for something specific.

Business Model Terms

B2B (Business-to-Business): A model where one business sells products or services to another business rather than to individual consumers. Common in wholesale, manufacturing, and software. B2B transactions typically involve longer sales cycles and higher order values than B2C.

B2C (Business-to-Consumer): The traditional retail model applied to e-commerce — a business sells directly to individual customers. Most Shopify stores operate as B2C.

C2C (Consumer-to-Consumer): A model where individuals sell to other individuals, typically through a marketplace platform. eBay, Craigslist, Facebook Marketplace, and Depop are C2C platforms.

C2B (Consumer-to-Business): A less common model where individuals offer products or services to businesses. Freelance platforms like Upwork and Fiverr operate on this model, as do influencer marketing arrangements where creators sell sponsored content to brands.

D2C / DTC (Direct-to-Consumer): A business model where brands sell directly to end consumers, bypassing traditional wholesale and retail intermediaries. DTC brands control the full customer experience — from product development to post-purchase support — and typically sell through their own website rather than through third-party retailers or marketplaces.

Dropshipping: A fulfillment model where the retailer doesn't hold physical inventory. When a customer places an order, the retailer purchases from a supplier who ships directly to the customer. Lower overhead, but typically lower margins and less control over shipping experience.

Brick and Mortar: A business with at least one physical retail location. Often used to contrast with pure online retailers, or to describe hybrid brands operating both online and offline.

Shopping & Checkout Terms

Cart Abandonment: When a customer adds items to an online shopping cart but leaves without completing the purchase. The average cart abandonment rate across e-commerce is consistently above 70%. Understanding why customers abandon — unexpected shipping costs, complicated checkout, required account creation — is a high-leverage optimization opportunity.

BOPIS (Buy Online, Pick Up In-Store): A fulfillment option that lets customers order online and collect in person at a physical location. Reduces shipping time and cost while driving store traffic.

BNPL (Buy Now, Pay Later): Financing options like Afterpay, Klarna, and Shop Pay Installments that allow customers to split purchases into interest-free installments. Shown to increase conversion rates and average order value, particularly for higher-ticket items.

Conversion: The moment a visitor completes a desired action — most commonly making a purchase. A “conversion” can also refer to an email signup, a free trial start, or any other goal action depending on the context.

Conversion Rate: The percentage of visitors who complete a desired action. Calculated as (conversions ÷ sessions) × 100. Average e-commerce conversion rates typically fall between 1–3%, though this varies significantly by industry, traffic source, and price point.

Conversion Funnel: The sequence of steps a customer moves through from first awareness of a brand to completing a purchase. Typically broken into stages: awareness → consideration → decision → purchase. Identifying where users drop off in the funnel is key to improving overall conversion rate.

Call-to-Action (CTA): A prompt designed to encourage a specific user action — “Add to Cart,” “Shop Now,” “Get 20% Off,” etc. CTAs appear in ads, emails, landing pages, and product pages.

m-Commerce (Mobile Commerce): Purchasing conducted through smartphones or tablets. Mobile accounts for the majority of e-commerce traffic globally, making mobile UX optimization a core priority for any online store.

Marketing & Analytics Terms

A/B Testing: Running two versions of a page, email, or ad simultaneously to determine which performs better. Commonly used to test product page layouts, subject lines, ad creative, and pricing displays. Results are only statistically meaningful with sufficient traffic volume.

Affiliate Marketing: A performance-based channel where publishers (bloggers, content sites, influencers) earn a commission for driving traffic or sales to a retailer via tracked links. The retailer only pays when a conversion occurs.

AOV (Average Order Value): The average dollar amount per order, calculated as total revenue ÷ number of orders. Increasing AOV through upsells, bundles, or free shipping thresholds is often more cost-efficient than acquiring new customers.

Big Data: The large volumes of customer, transaction, and behavioral data generated by e-commerce operations. Analyzing this data can surface patterns in buying behavior, identify churn risks, and inform personalization strategies.

Churn Rate: The percentage of customers who stop purchasing from a brand over a given period. High churn is expensive — it forces constant new customer acquisition to maintain revenue. Reducing churn by improving retention is usually more profitable than growing top-of-funnel traffic.

Click-Through Rate (CTR): The percentage of people who click a link after seeing it. Used to measure the effectiveness of ads, email subject lines, and organic search listings. Calculated as (clicks ÷ impressions) × 100.

Cross-Selling: Recommending related or complementary products to a customer who is actively purchasing or has recently purchased. A customer buying a camera is cross-sold a memory card or camera bag. Increases AOV without requiring additional customer acquisition.

Customer Acquisition Cost (CAC): The total marketing and sales spend required to acquire one new customer. Calculated as total spend ÷ number of new customers. Should always be evaluated relative to Customer Lifetime Value to determine whether acquisition is sustainable.

Customer Lifetime Value (CLV / LTV): The total revenue a business can expect from a single customer over the entire relationship. Higher CLV justifies higher CAC. Brands with strong LTV can afford to acquire customers at a loss and profit over time — brands with weak LTV cannot.

Customer Retention: The strategies and tactics used to keep existing customers purchasing over time. Includes loyalty programs, email marketing, post-purchase experiences, and product quality. Retained customers are typically cheaper to serve and more likely to refer others.

KPI (Key Performance Indicator): A measurable metric used to evaluate progress toward a specific business goal. Common e-commerce KPIs include conversion rate, AOV, CAC, CLV, ROAS, and churn rate.

Net Promoter Score (NPS): A measure of customer loyalty based on one question: “How likely are you to recommend us to a friend?” Respondents score 0–10. Scores of 9–10 are Promoters, 7–8 are Passives, and 0–6 are Detractors. NPS = % Promoters − % Detractors.

ROI (Return on Investment): A measure of the financial return relative to cost. In e-commerce, commonly applied to marketing campaigns, technology investments, and product development. Calculated as (net gain ÷ cost) × 100.

SEO (Search Engine Optimization): The practice of optimizing a website to rank higher in unpaid (organic) search results. For e-commerce, this typically includes product page optimization, content creation, site speed, and link building.

Omni-Channel: A commerce strategy that provides customers with a unified experience across all touchpoints — online store, mobile, social media, physical retail, and customer service. Distinguished from multi-channel in that the channels are integrated rather than operating independently.

Customer Experience Terms

Brand Loyalty: A customer's tendency to repeatedly choose one brand over competitors. Strong brand loyalty reduces CAC over time and creates organic word-of-mouth. Built through consistent product quality, customer service, and brand experience.

Bundling: Packaging multiple products together, typically at a slight discount, to encourage higher order values and help customers find complementary items. Effective for both AOV improvement and inventory management.

Buyer Persona: A semi-fictional profile of an ideal customer, built from customer data and research. Used to guide product development, marketing messaging, and channel strategy. A useful tool for aligning a team around who they're actually building for.

Chatbot: An AI-powered tool that handles customer service inquiries, product recommendations, and basic support interactions automatically. Quality varies widely — well-implemented chatbots reduce support costs and improve response time; poorly implemented ones frustrate customers.

Consumer Behavior: The study of how, why, and when customers make purchasing decisions. Includes motivations, decision-making patterns, and post-purchase behavior. Understanding consumer behavior informs everything from product positioning to checkout flow design.

CRM (Customer Relationship Management): A system for managing interactions with customers and prospects. CRM platforms (like Klaviyo, HubSpot, or Salesforce) store customer data, purchase history, and communication records, enabling more personalized marketing and support.

Cross-Shopping: When a customer compares products or prices across multiple brands or retailers before purchasing. Common in higher-consideration categories. Understanding where your customers cross-shop helps identify your actual competitive set.

Frequent Buyer / Loyalty Programs: Structured programs that reward repeat purchases with points, discounts, or exclusive perks. Effective for increasing purchase frequency and CLV when the rewards align with what customers actually value.

User Experience (UX): The overall experience a customer has when interacting with your brand — from navigating your website to receiving a package to contacting support. Poor UX at any stage increases churn. Strong UX compounds: each positive interaction increases the likelihood of return.

Fulfillment & Operations Terms

Fulfillment: The end-to-end process of storing, picking, packing, and shipping orders to customers. Can be handled in-house, by a third-party logistics provider (3PL), or by a marketplace like Amazon.

FBA (Fulfillment by Amazon): A service where Amazon handles storage, picking, packing, and shipping on behalf of sellers. Products fulfilled by Amazon are eligible for Prime shipping. FBA fees vary by product size and category.

FBM (Fulfillment by Merchant): When the seller manages all aspects of order fulfillment directly. Offers more control over packaging, shipping speed, and customer experience, but requires operational infrastructure.

3PL (Third-Party Logistics): An outsourced fulfillment partner that handles warehousing, picking, packing, and shipping on behalf of a brand. Commonly used by DTC brands that have outgrown self-fulfillment but don't want to manage their own warehouse.

Amazon-Specific Terms

BSR (Amazon Bestseller Ranking): A rank assigned to products in Amazon's catalog based on recent sales velocity. A product receives its BSR after its first sale; the rank updates hourly. A lower BSR number means more sales. Useful for gauging category demand and competitive positioning.

Amazon PPC (Pay-Per-Click): Amazon's paid advertising system, where sellers bid on search keywords to have their products appear prominently in search results. The seller pays only when a shopper clicks the ad. Competing effectively in Amazon PPC requires keyword research, bid management, and ongoing optimization.

Amazon SEO: The practice of optimizing product listings — titles, bullet points, descriptions, backend keywords, and images — to rank higher in Amazon's organic search results (A9 algorithm). Unlike Google SEO, Amazon SEO is heavily influenced by sales history and conversion rate.

Buy Box: The purchase button on an Amazon product detail page. When multiple sellers offer the same product, Amazon awards the Buy Box to one seller based on price, fulfillment method, seller rating, and inventory. Winning the Buy Box is critical for sales volume on marketplace listings.

Lightning Deals: Time-limited, quantity-limited promotions featured prominently on Amazon, particularly during events like Prime Day or Black Friday. High-visibility but competitive to access and require significant inventory commitment.

Cyber Monday: The Monday following Thanksgiving — one of the highest-volume online shopping days of the year. Typically paired with Black Friday as the peak of the holiday sales season for e-commerce brands.

Want to Go Deeper?

This glossary covers the terms you'll encounter most often, but e-commerce is a broad field. If you're looking for more detailed definitions of specific concepts, First Pier maintains a full e-commerce glossary covering 200+ terms — from attribution modeling to zero-party data. If you're ready to put these concepts into practice for your Shopify store, get in touch.