---
title: "World Book Day Costumes Adults — £77K/yr Amazon UK Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/uk/fashion/world-book-day-costumes-adults"
last_updated: "2026-07-31T10:46:34.419Z"
locale: en
meta:
description: "Niche score 23/100 · £77K/yr market · 1.1M searches/yr · £14.28 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 23/100 · £77K/yr market · 1.1M searches/yr · £14.28 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "World Book Day Costumes Adults — £77K/yr Amazon UK Niche (2026) - Flapen"
---
# **world book day costumes adults**
**Skip it**
Soft demand (-99.7% this quarter) — this niche doesn't clear our bar today.
Market size 19Growth 0Conversion 6Competition 0Returns 40Price range 57Avg price 69Brand share 0Review moat 74Quality gap 58
**Review moat**
**Good****526.75**
avg incumbent reviews — the moat a new listing must climb
**Avg price**
**Good****£14.28**
avg listing price — sweet spot $15–$100
**Quality gap**
**Good****4.4★**
avg incumbent rating — lower means beatable quality
**Price range**
**Good****£9.35–£22.50**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Returns**
**Okay****3.8%**
return rate — above 5% kills the launch gate
**Market size**
**Bad****£77K**
£77K/yr · 1.1M searches
**Conversion**
**Bad****0.5%**
search→purchase rate — share of searches ending in a sale
**Growth**
**Bad****-99.7%**
90-day search growth — must beat 0% to launch
**Competition**
**Bad****100%**
top-5 click share — a locked-up shelf
**Brand share**
**Bad****100%**
top-5 brand share — brand-locked demand
**Signals**[** Low Review Barrier**](https://flapen.com/research/niches?market=uk&signal=low_review_barrier "Top brand's reviews < 500")
According to Flapen's Amazon United Kingdom niche tracking, world book day costumes adults is a £77K/yr Amazon United Kingdom market (1.1M searches/yr). The top 5 brands hold 100% of demand. Verdict: Skip it — 23/100.
Data updated Jul 23, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **world book day costumes adults market data**
- **Units sold / yr**
- **5K–6K**
- avg 0–100/product
- **Revenue / yr**
- **£71K–£86K**
- units × avg price
- **Conversion rate**
- **0.5%**
- **Avg BSR**
- **#198**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **50%**
- **Out of stock**
- **19.6%**
- **Avg brand age**
- **36 months**
- **Avg seller age**
- **199 days**
## **Competition & brand share**
The top 5 products capture 100% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**4 **▲rising
**Sellers**
**19**
**Top-5 brand share**
**100%**
Top 20: 100%
**Top-5 click share**
**100%**
Top 20: 100%
**Open market**
**0%**
- PENGMAI85% - Zidoley5% - DABAOOU5% - Smiffys5%
## **Demand**
Weekly Amazon search volume, last 21 weeks — -99.7% search growth over the last 90 days.
400K300KMar '26Mar '26Apr '26May '26May '26Jun '26Jul '26
[**Open Trend **](https://flapen.com/research/uk/fashion/world-book-day-costumes-adults/trend)
## **Top world book day costumes adults search terms**
- **world book day costumes adults**505K/yr-99.7%0.1% conv. - **adult world book day costumes women**178K/yr-99.8%0.0% conv. - **fancy dress costumes for world book day**45K/yr-99.2%0.3% conv. - **world book day costumes for adults**55K/yr-99.6%0.0% conv. - **adult book day costumes**15K/yr-98.6%0.0% conv. - **world book day costumes for women**68K/yr-99.7%0.0% conv. - **world book day adult costume**26K/yr-99.4%0.0% conv. - **adults world book day costume**22K/yr-99.5%0.0% conv. - **teachers world book day costumes**27K/yr-99.6%0.0% conv. - **adult world book day costumes**31K/yr-99.7%0.0% conv. [**All search terms **](https://flapen.com/research/uk/fashion/world-book-day-costumes-adults/search-terms)
## **Top world book day costumes adults products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%25%£19K50%£39K75%£58K100%£77K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 4 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**PENGMAI Dragon Costume One Piece Pyjamas for Women Men Adult Animal Onesie Halloween Cosplay Costumes Homewear Jumpsuit**PENGMAI**£22.50**4.2★249 rev](https://www.amazon.co.uk/dp/B0DCSGGTCK) [2**Crayon Costume Adult 3Pcs Colorful Crayon Fancy Dress Include Crayon Apron Funny Cone Hat And Striped Socks Unisex World Book Day Costumes Halloween Party Christmas Group Cosplay Outfits (Pink)**Zidoley**£9.35**4.5★50 rev](https://www.amazon.co.uk/dp/B0GF89YD8J) [3**DABAOOU 7pcs Wizard Cape Costume Accessories Set Halloween World Book Day Fancy Dress Adults Black Hooded Cape Scarf Magic Wand Glasses Tie Hat and Tattoo Stickers Themed Party Cosplay Outfit**DABAOOU**£11.76**4.7★26 rev](https://www.amazon.co.uk/dp/B0G4K9CT9R) [4**Smiffys Red Riding Hood Costume Red with Longer Length Dress & Cape Fairytale Wings and Wands Fancy Fancy Dress Adult Dress Up Costumes**Smiffys**£13.50**4.2★1,782 rev](https://www.amazon.co.uk/dp/B01MF62F8C)
### **Newest**
by launch date
[**Crayon Costume Adult 3Pcs Colorful Crayon Fancy Dress Include Crayon Apron Funny Cone Hat And Striped Socks Unisex World Book Day Costumes Halloween Party Christmas Group Cosplay Outfits (Pink)**Zidoley**£9.35**50 rev6mo ago](https://www.amazon.co.uk/dp/B0GF89YD8J) [**DABAOOU 7pcs Wizard Cape Costume Accessories Set Halloween World Book Day Fancy Dress Adults Black Hooded Cape Scarf Magic Wand Glasses Tie Hat and Tattoo Stickers Themed Party Cosplay Outfit**DABAOOU**£11.76**26 rev7mo ago](https://www.amazon.co.uk/dp/B0G4K9CT9R) [**PENGMAI Dragon Costume One Piece Pyjamas for Women Men Adult Animal Onesie Halloween Cosplay Costumes Homewear Jumpsuit**PENGMAI**£22.50**249 rev1y ago](https://www.amazon.co.uk/dp/B0DCSGGTCK) [**Smiffys Red Riding Hood Costume Red with Longer Length Dress & Cape Fairytale Wings and Wands Fancy Fancy Dress Adult Dress Up Costumes**Smiffys**£13.50**1,782 rev9y ago](https://www.amazon.co.uk/dp/B01MF62F8C)
### **Trending**
90-day click momentum
[**PENGMAI Dragon Costume One Piece Pyjamas for Women Men Adult Animal Onesie Halloween Cosplay Costumes Homewear Jumpsuit**PENGMAI**£22.50**4.2★**▲ 376%**](https://www.amazon.co.uk/dp/B0DCSGGTCK) [**DABAOOU 7pcs Wizard Cape Costume Accessories Set Halloween World Book Day Fancy Dress Adults Black Hooded Cape Scarf Magic Wand Glasses Tie Hat and Tattoo Stickers Themed Party Cosplay Outfit**DABAOOU**£11.76**4.7★**▼ 77%**](https://www.amazon.co.uk/dp/B0G4K9CT9R) [**Crayon Costume Adult 3Pcs Colorful Crayon Fancy Dress Include Crayon Apron Funny Cone Hat And Striped Socks Unisex World Book Day Costumes Halloween Party Christmas Group Cosplay Outfits (Pink)**Zidoley**£9.35**4.5★**▼ 77%**](https://www.amazon.co.uk/dp/B0GF89YD8J) [**Smiffys Red Riding Hood Costume Red with Longer Length Dress & Cape Fairytale Wings and Wands Fancy Fancy Dress Adult Dress Up Costumes**Smiffys**£13.50**4.2★**▼ 88%**](https://www.amazon.co.uk/dp/B01MF62F8C)
## **What buyers say about world book day costumes adults**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Value For Money**23%
*“Great value”*
**Quality-Overall**21%
*“Good quality”*
**Size-Overall**12%
*“Accurate size”*
**Color**9%
*“Nice colour”*
**Fun/Entertainment Experience**5%
*“£10.99, voucher £10.44 at time of review, makes this a full of fun costume for a teen upwards”*
**Comfort-Overall**5%
*“So comfortable”*
**Material Quality**4%
*“Quality material for the cost”*
**Durability**3%
*“The quality of the items are fairly strong a durable”*
**Ease Of Use**3%
*“Simple and easy”*
**Design-Overall**3%
*“The colours and overall design look fantastic and really bring the whole costume together”*
### **What buyers complain about **
**Size-Overall**15%
*“so it was far too long for my child”*
**Quality-Overall**10%
*“not an excellent quality item”*
**Certifications**7%
*“isn't a licensed product”*
**Thickness**7%
*“the scarf very thin”*
**Strength**5%
*“though it felt a little flimsy”*
### **Top return reasons **
**Size-Overall**82%
**Quality-Overall**9%
**Material Quality**4%
**Thin**4%
**Value For Money**2%
**Color**2%
**Defective Material/Parts**1%
## **Common questions**
- **Is world book day costumes adults profitable to sell on Amazon United Kingdom?**
- The niche generates £77K/yr across 4 tracked products. 0 of 2 products launched in the last 360 days are still selling. 90-day search growth is -99.7%. Flapen's verdict: Skip it (23/100).
- **How competitive is the world book day costumes adults niche?**
- 4 brands and 19 sellers compete. The top 5 products take 100% of clicks and top 5 brands hold 100% of demand.
- **What do buyers complain about in world book day costumes adults?**
- Top complaints mined from reviews: Size-Overall, Quality-Overall, Certifications. The return rate is 3.8%.
- **What does it cost to enter the world book day costumes adults niche?**
- Listings span £9.35–£22.50; the average listing price is £14.28 (sweet spot $15–$100). The average incumbent carries 527 reviews — the moat a new listing must climb.
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