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.

world book day costumes adults

Skip it

Soft demand (-99.7% this quarter) — this niche doesn't clear our bar today.

Review moat

Good526.75

avg incumbent reviews — the moat a new listing must climb

Avg price

Good£14.28

avg listing price — sweet spot $15–$100

Quality gap

Good4.4★

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

Okay3.8%

return rate — above 5% kills the launch gate

Market size

Bad£77K

£77K/yr · 1.1M searches

Conversion

Bad0.5%

search→purchase rate — share of searches ending in a sale

Growth

Bad-99.7%

90-day search growth — must beat 0% to launch

Competition

Bad100%

top-5 click share — a locked-up shelf

Brand share

Bad100%

top-5 brand share — brand-locked demand

Signals Low Review Barrier

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

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

Top-5 brand share

100%

Top 20: 100%

Top-5 click share

100%

Top 20: 100%

Open market

PENGMAI85%
Zidoley5%
DABAOOU5%
Smiffys5%

Demand

Weekly Amazon search volume, last 21 weeks — -99.7% search growth over the last 90 days.

Open Trend

Top world book day costumes adults search terms

world book day costumes adults505K/yr -99.7%0.1% conv.
adult world book day costumes women178K/yr -99.8%0.0% conv.
fancy dress costumes for world book day45K/yr -99.2%0.3% conv.
world book day costumes for adults55K/yr -99.6%0.0% conv.
adult book day costumes15K/yr -98.6%0.0% conv.
world book day costumes for women68K/yr -99.7%0.0% conv.
world book day adult costume26K/yr -99.4%0.0% conv.
adults world book day costume22K/yr -99.5%0.0% conv.
teachers world book day costumes27K/yr -99.6%0.0% conv.
adult world book day costumes31K/yr -99.7%0.0% conv.

All 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.

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

PENGMAI Dragon Costume One Piece Pyjamas for Women Men Adult Animal Onesie Halloween Cosplay Costumes Homewear Jumpsuit

PENGMAI£22.504.2★249 rev

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£9.354.5★50 rev

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£11.764.7★26 rev

Smiffys Red Riding Hood Costume Red with Longer Length Dress & Cape Fairytale Wings and Wands Fancy Fancy Dress Adult Dress Up Costumes

Smiffys£13.504.2★1,782 rev

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£9.3550 rev

6mo ago

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£11.7626 rev

7mo ago

PENGMAI Dragon Costume One Piece Pyjamas for Women Men Adult Animal Onesie Halloween Cosplay Costumes Homewear Jumpsuit

PENGMAI£22.50249 rev

1y ago

Smiffys Red Riding Hood Costume Red with Longer Length Dress & Cape Fairytale Wings and Wands Fancy Fancy Dress Adult Dress Up Costumes

Smiffys£13.501,782 rev

9y ago

What buyers say about world book day costumes adults

What buyers praise and complain about, mined from review topics.

What buyers love

Value For Money23%

“Great value”

Quality-Overall21%

“Good quality”

Size-Overall12%

“Accurate size”

Color9%

“Nice colour”

Fun/Entertainment Experience5%

“£10.99, voucher £10.44 at time of review, makes this a full of fun costume for a teen upwards”

Comfort-Overall5%

“So comfortable”

Material Quality4%

“Quality material for the cost”

Durability3%

“The quality of the items are fairly strong a durable”

Ease Of Use3%

“Simple and easy”

Design-Overall3%

“The colours and overall design look fantastic and really bring the whole costume together”

What buyers complain about

Size-Overall15%

“so it was far too long for my child”

Quality-Overall10%

“not an excellent quality item”

Certifications7%

“isn't a licensed product”

Thickness7%

“the scarf very thin”

Strength5%

“though it felt a little flimsy”

Top return reasons

Size-Overall82%

Quality-Overall9%

Material Quality4%

Thin4%

Value For Money2%

Color2%

Defective Material/Parts1%

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.