OnBuy

Overview

OnBuy is a UK-founded online marketplace that positions itself as a fairer, seller-friendly alternative to Amazon. Launched in November 2016 by founder and CEO Cas Paton, it is a pure third-party (3P) marketplace: OnBuy holds no inventory of its own and does not compete with the retailers who sell on it. Originally headquartered in Poole/Bournemouth, Dorset, the company has since moved its HQ to London and opened offices in Manchester and Dublin, plus a planned New York base as it pushes into Europe and North America. It sells across most general-merchandise categories (electronics, home & garden, DIY, health & beauty, toys, and more) and reached roughly US$200m in gross merchandise value in 2025.

What they’re known for

OnBuy is best known for two distinctive positions in a market dominated by Amazon:

• A genuine “level playing field” for sellers. Unlike Amazon, OnBuy never lists its own products against merchants. Its recurring line — “every single pound that moves through the company is a pound for a retailer, not for OnBuy” — anchors its brand. Products use a shared catalogue where buyers find an item once and then choose among competing sellers.
• Cashback on every purchase. In July 2023 OnBuy became the first marketplace to offer cashback on all purchases (up to 7.5%), funded by OnBuy itself rather than by sellers, with no third-party tracking. This customer-loyalty engine is central to its differentiation and international pitch, and it had paid out over £1.6m in cashback across the UK by late 2024.

History

• 2016 — OnBuy launches in November, founded by Cas Paton in Dorset as an Amazon alternative.
• 2020 — Named the UK’s fastest-growing business in a SimilarWeb report; hit ~700% growth in October vs. the prior year; valuation reached ~£115m after a Series A.
• 2021 — Raises a £35m Series A+ (mix of debt and equity) at a ~£132m valuation, targeting unicorn status; reports £155m annualised GMV on only ~£8m of prior investment, 7,000+ retailers and 36m+ products.
• 2023 — Launches marketplace-funded cashback (up to 7.5%); records its first-ever profitable month in October; closes strategic investment from a NASDAQ-listed tech player.
• 2024 — Partners with Google Cloud; begins European rollout (localised sites in French, German, Spanish, Italian, Dutch); Q4 2024 revenue of £44m, up 37% YoY, with ~£19m gross profit.
• 2025 — Reaches 21 European markets after adding 8 new countries; confirms HQ move from Bournemouth to London and a New York base; acquires electronics brand Comet from Misco Technologies (Cas Paton becomes Comet CEO), pledging £10m to relaunch it; ~US$200m GMV for the year.

Business model

OnBuy is a commission-based, third-party marketplace — it earns money on transactions rather than on its own retail sales. Revenue comes from:

• Category sale/referral fees, generally lower than Amazon’s. Public seller guides cite category fees roughly in the 5–15% range depending on category (e.g. consumer electronics on the lower end), with a small minimum per item.
• Seller subscription plans (e.g. a Standard and a higher Partner tier), where the Partner plan boosts placement in OnBuy’s Buy Box, analogous to Amazon Prime prioritisation.

Distinctively, OnBuy has historically had no paid advertising / sponsored-listings platform — products rank organically on price, seller rating and delivery speed — and it charges no listing fees. Because it is purely 3P, sellers manage their own stock, pricing and fulfilment while OnBuy provides the storefront, checkout, and (uniquely) shopper cashback. Around 51% of GMV reportedly comes from returning customers.

Why it succeeded

OnBuy’s growth reflects a deliberately narrow strategic wedge against Amazon rather than a head-on fight:

• Clear seller-side differentiation. By promising never to compete with its own merchants and keeping fees transparent and lower, OnBuy attracted retailers wary of Amazon’s first-party competition and rising ad costs — a message echoed across its funding announcements and its GS1 UK profile.
• A customer loyalty hook rivals lacked. The cashback proposition gave shoppers a concrete reason to return, driving the high share of repeat GMV and giving OnBuy a marketing story distinct from price-only competition.
• Capital-efficient early growth. It reached £155m annualised GMV on only ~£8m of investment before its £35m Series A+, demonstrating unusually lean unit economics for a marketplace and validating investor appetite (Fuel Ventures, Bring Ventures/Norway Post, Guy Hands, Klarna’s Knut Frängsmyr).
• AI-led operating leverage. Deeper AI integration (autocategorisation reaching ~93% accuracy across 20m+ products, plus a Google Cloud partnership) helped it reach profitability in 2023 and expand into 21 European markets without proportionate cost growth — Paton estimated AI saved the business ~£8m.

Notable facts

• Reached US$200m GMV in 2025, with a projected 40% increase for 2026.
• 51% of GMV comes from returning customers.
• Raised a £35m Series A+ in 2021 at a ~£132m valuation after hitting £155m annualised GMV on just ~£8m of prior funding.
• Q4 2024 sales of £44m (up 37% YoY) with ~£19m gross profit; December 2025 revenues alone reached £19m.
• First marketplace to offer cashback on all purchases (up to 7.5%, launched July 2023), £1.6m+ paid out in the UK by late 2024.
• Operates across 21 European markets; named to the 2025 Sunday Times 100 Tech list of Britain’s fastest-growing private tech companies.
• Acquired the Comet electronics brand in 2025, reinvesting £10m to relaunch it within the OnBuy marketplace.

Links

Title	URL	Type	Note
OnBuy official marketplace	https://www.onbuy.com	official-site	Canonical site; homepage uses anti-bot protection (403 to automated fetches) but is the live marketplace referenced across all sources below
OnBuy: the marketplace built for sellers in a marketplace driven world (GS1 UK)	https://www.gs1uk.org/insights/news/OnBuy-the-marketplace-built-for-sellers-in-a-marketplace-driven-world	article	Business model, GMV, 51% returning-customer stat
Big Interview: Cas Paton, Founder & CEO, OnBuy (Retail Gazette)	https://www.retailgazette.co.uk/blog/2020/11/big-interview-cas-paton-founder-ceo-onbuy/	article	Founding story, hybrid catalogue model, 2020 growth
OnBuy eyes unicorn status as it raises £35 million (Retail Technology Innovation Hub)	https://retailtechinnovationhub.com/home/2021/7/13/onbuy-eyes-unicorn-status-as-it-raises-35-million	article	£35m Series A+, £155m GMV, investor list
OnBuy raises £35M in impressive Series A+ funding round (PR Newswire)	https://www.prnewswire.com/news-releases/onbuy-raises-ps35m-in-impressive-series-a-funding-round-864204016.html	news	Official funding announcement, “level playing field” positioning
Exclusive: OnBuy CEO Cas Paton on launching cashback (ChannelX)	https://channelx.world/2023/07/exclusive-onbuy-ceo-cas-paton-on-launching-cashback/	article	Details of marketplace-funded cashback (up to 7.5%)
Disrupting the e-commerce market: OnBuy boss talks first profitable month (Retail Technology Innovation Hub)	https://retailtechinnovationhub.com/home/2023/11/10/disrupting-the-e-commerce-market-onbuy-boss-cas-paton-talks-first-ever-profitable-month-and-plans-for-2024	article	First profitable month (Oct 2023), strategic investment
OnBuy follows Google Cloud partnership with international expansion (Retail Technology Innovation Hub)	https://retailtechinnovationhub.com/home/2024/10/21/onbuy-follows-google-cloud-partnership-with-international-expansion-across-eu-and-north-america	article	Google Cloud partnership, EU + North America expansion, cashback payouts
OnBuy reveals growth, profitability and new HQ (ChannelX)	https://channelx.world/2025/01/onbuy-reveals-growth-profitability-and-new-hq/	news	Q4 2024 £44m sales, profitability, HQ to London + New York, AI savings
OnBuy accelerates European rollout with launch into 8 new markets (BusinessCloud)	https://businesscloud.co.uk/news/onbuy-accelerates-european-rollout-with-launch-into-8-new-markets/	news	Expansion to 21 European countries, growth metrics
British marketplace OnBuy is launching in eight new countries (RetailDetail EU)	https://www.retaildetail.eu/news/general/british-marketplace-onbuy-is-launching-in-eight-new-countries/	news	8 new markets, cashback differentiation, 21-country reach
OnBuy: ‘30% daily growth in key European markets’ (Ecommerce News EU)	https://ecommercenews.eu/onbuy-30-daily-growth-in-key-european-markets/	news	European growth, localised sites, Q4 2024 financials
OnBuy founder becomes Comet CEO following acquisition (Retail Week)	https://www.retail-week.com/people/onbuy-founder-becomes-comet-ceo-following-acquisition/7048772.article	news	2025 Comet acquisition and £10m relaunch