OnBuy, B&Q, Temu: Hidden Marketplace Opportunities for UK Sellers

Most UK brands' marketplace strategy stops at Amazon and eBay. There's nothing wrong with that — those are the volume channels. But the brands we work with that successfully diversify away from Amazon dependence usually do so by adding 2-3 secondary marketplaces that fly under most sellers' radar. These are three of the most under-rated.

Why look beyond Amazon and eBay

Three real reasons UK brands diversify their marketplace mix:

1. Amazon dependence is a business risk. Account suspensions, fee increases, or competitive pressure can wipe a brand if Amazon is 70%+ of revenue.
2. Lower competition = higher margins. Secondary marketplaces have fewer sellers, less aggressive pricing pressure, and customers who haven't been trained to expect lowest-price-wins.
3. Different customer demographics. Each marketplace attracts a different customer profile — broadening reach matters for brands trying to grow.

The downside: each marketplace requires operational lift (listings, customer service, fulfilment, returns) that adds up. Don't add a channel you can't operate properly.

OnBuy — the British alternative

OnBuy is a UK-headquartered marketplace explicitly positioning as the British Amazon alternative. It's smaller (~3-5% of Amazon's UK GMV), but has carved out a real audience.

The numbers

• Monthly visitors: ~5-8 million
• Active sellers: ~4,000-6,000
• Seller fees: 5-9% commission depending on category + £19/month subscription
• Setup time: 2-3 weeks for account approval and initial listings

Where it works well

OnBuy works best for:

• Established UK brands with consumer recognition
• Products in the £20-150 price band
• Categories where Amazon is saturated (electronics, beauty, home essentials)
• Brands wanting to escape Amazon's per-unit fees on lower-margin items

Real numbers from a client account

Deep Fresh UK launched on OnBuy in 2025 alongside Amazon. After 6 months:

• Monthly OnBuy revenue: £3,200 (vs Amazon's £24,000 from same product range)
• OnBuy net margin: 22% (vs Amazon's 14% on equivalent SKUs)
• Customer service volume: roughly equivalent per £1k of revenue
• Time to break even on setup: 8 weeks

Not transformational, but consistent and incremental. For a brand managing 5+ marketplaces, OnBuy is worth the operational effort.

B&Q Marketplace — home & DIY only

B&Q opened a third-party marketplace in 2022 (after acquiring CastoramaDIY's model). It's narrow but high-intent: customers visiting B&Q.com are actively shopping for home improvement.

The numbers

• Monthly visitors: ~25-30 million (huge — B&Q is a major UK retailer site)
• Active marketplace sellers: ~1,500 (low for the traffic size)
• Seller fees: 8-15% commission depending on category, no monthly fee
• Setup time: 4-6 weeks for approval (B&Q vets sellers heavily)

Where it works well

B&Q is restrictive — they only accept categories that fit their store positioning (home, garden, DIY, hardware, cleaning, paint, decor). If your products fit, the competition is dramatically lower than Amazon.

Real numbers from a client account

An anonymous cleaning products client launched on B&Q in 2025:

• Monthly B&Q revenue after 6 months: £4,200
• B&Q net margin: 24% (highest of all their marketplace channels)
• Conversion rate from B&Q traffic: 4.8% (above their own Shopify's 3.1%)
• Time to break even on setup: 12 weeks (longer due to approval period)

The high conversion rate is the surprise — B&Q customers come with high purchase intent. The downside is the narrow category fit.

Temu — high volume, thin margin

The newcomer everyone has opinions about. Temu launched UK seller acquisition in 2024 and now has a UK marketplace operating alongside its direct-from-China model.

The numbers

• Monthly UK visitors: ~30-40 million (extraordinary growth)
• UK seller count: Growing rapidly, ~2,000-5,000 estimated
• Seller fees: Low headline (2-5%), but operationally complex
• Setup time: Fast (1-2 weeks) but documentation-heavy

The honest assessment

Temu is hard. The pros: massive traffic, low fees, fast setup. The cons:

• Customer price expectations are extremely low — you're competing against direct-from-China pricing
• Customer service expectations are demanding; ratings affect listing visibility
• Returns are operationally complex (some go back to a Temu UK hub, not directly to seller)
• Higher fraud and chargeback rates than other marketplaces

Where it actually works

Temu works for UK brands that:

• Have products priced in the £5-25 band
• Have high-margin products where they can absorb low pricing
• Have automated/efficient fulfilment
• Accept that Temu is a volume channel, not a brand-building one

For everyone else, Temu is more trouble than it's worth.

Which one fits which brand

You sell premium consumer goods (£30-150 AOV)

Try OnBuy. The audience is closest to your Amazon customer, less competition, better margins.

You sell home, DIY, garden or hardware products

B&Q Marketplace is mandatory. The category match and traffic quality is exceptional. Don't ignore this.

You sell low-priced commodity products with margin headroom

Try Temu. Treat it as a volume play, not a brand experience.

You sell anything else

OnBuy first, B&Q only if there's a category fit, skip Temu.

"Most UK brands could profitably operate 4-5 marketplaces. Most operate 1-2. The gap is operational capacity, not opportunity."