21st birthday cards for her
Worth a lookShows low returns (0.1%), but prices mostly outside the sweet spot ($2.10–$11.62) keeps it on the watch list.
Returns
Incredible0.1%return rate — above 5% kills the launch gate
Brand share
Great43%top-5 brand share — no brand owns this niche
Conversion
Great9.6%search→purchase rate — share of searches ending in a sale
Review moat
Great372.51avg incumbent reviews — the moat a new listing must climb
Competition
Great38%top-5 click share — an open shelf
Market size
Okay£140K£140K/yr · 340K searches
Growth
Bad-4.6%90-day search growth — must beat 0% to launch
Quality gap
Bad4.7★avg incumbent rating — lower means beatable quality
Avg price
Bad£4.29avg listing price — sweet spot $15–$100
Price range
Bad£2.10–£11.62cheapest to priciest tracked listing — scored on the share inside $15–$100
According to Flapen's Amazon United Kingdom niche tracking, 21st birthday cards for her is a £140K/yr Amazon United Kingdom market (340K searches/yr). The top 5 brands hold 43% of demand. Verdict: Worth a look — 54/100.
Data updated Jul 29, 2026 · scored weekly · How we score niches
21st birthday cards for her market data
- Units sold / yr
- 25K–30K
- avg 250–500/product
- Revenue / yr
- £107K–£129K
- units × avg price
- Conversion rate
- 9.6%
- Avg BSR
- #1,886
- Page quality
- 0%
- Prime
- 94%
- Sponsored
- 80%
- Out of stock
- 4.5%
- Avg brand age
- 26 months
- Avg seller age
- 177 days
Competition & brand share
Clicks spread well past the top 5 (38% combined) — an open shelf where new products get seen.Brands
35 falling
Sellers
67
Top-5 brand share
43%
Top 20: 87%
Top-5 click share
38%
Top 20: 73%
Open market
50%
- Belloxis11%
- Stuff49%
- HOMANGA9%
- UNMOT8%
- Virelle7%
- Me To You7%
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -4.6% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.6×
Top 21st birthday cards for her search terms
- 21st birthday card172K/yr
- 21st birthday cards for her57K/yr
- 21st birthday cards for him31K/yr
- 21st birthday card for her18K/yr
- 21st birthday card for him15K/yr
- 21 birthday card10K/yr
- 21st birthday cards9K/yr
- 21st birthday card male8K/yr
- happy 21st birthday card5K/yr
- 21st birthday card for men6K/yr
Top 21st birthday cards for her 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.
All 24 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
Belloxis 21st Birthday Gifts Grip Socks for Girls
Belloxis£5.674.6★655 rev
UNMOT 21st Birthday Card for Her Happy 21st Card for Girl with Envelope
UNMOT£3.354.5★127 rev
HOMANGA 21st Birthday Card 21st Birthday Gift for Men Women Vintage Back in 2005 Card with Envelope 21 Bday Card Decoration for Son Daughter Him Her 5×7 Inch
HOMANGA£3.394.6★54 rev
21st Birthday Cards for Women Pink Glitter Balloons
Stuff4£3.364.6★314 rev
3D 21st Birthday Card with Red Heart Balloon for Her Daughter Sister Granddaughter | Happy 21st Birthday Gift Card for Women Blank Inside with Envelope (14x14 cm)
Virelle£3.364.5★83 rev
Newest
by launch date
21st Birthday Card for Men & Women 3D Pop Up Birthday Greeting Card Black & Gold 21 Years Old Birthday Decorations & Gifts for Him or Her Ideal for Son Daughter Sister and Special Cousin
OLOSONG£6.1075 rev
Me To You Tatty Teddy 21 Today Luxury Gold Embellished Birthday Card 6 X 9 Inches - Official Collection
Me To You£2.106 rev
3D 21st Birthday Card with Red Heart Balloon for Her Daughter Sister Granddaughter | Happy 21st Birthday Gift Card for Women Blank Inside with Envelope (14x14 cm)
Virelle£3.3683 rev
YianHien 21st Birthday Card 3D Box Pop Up Birthday Card for Her
YianHien£5.77231 rev
Hierein 21st Birthday Card Pink 3D Pop Up 21st Birthday Cards for Her
Hierein£5.85137 rev
Trending
90-day click momentum21st Birthday Card for Men & Women 3D Pop Up Birthday Greeting Card Black & Gold 21 Years Old Birthday Decorations & Gifts for Him or Her Ideal for Son Daughter Sister and Special Cousin
OLOSONG£6.104.6★
Me To You Tatty Teddy 21 Today Luxury Gold Embellished Birthday Card 6 X 9 Inches - Official Collection
Me To You£2.105.0★
Belloxis 21st Birthday Gifts Grip Socks for Girls
Belloxis£5.674.6★
21st Birthday Cards for Women Pink Glitter Balloons
Stuff4£3.364.6★
HOMANGA 21st Birthday Card 21st Birthday Gift for Men Women Vintage Back in 2005 Card with Envelope 21 Bday Card Decoration for Son Daughter Him Her 5×7 Inch
HOMANGA£3.394.6★
What buyers say about 21st birthday cards for her
What buyers praise and complain about, mined from review topics.What buyers love
“Good quality card”
“Excellent value for money”
“Bright colours”
“a good size”
“Lovely Design”
“A nice gift”
“Unique and playful”
“exactly as described”
“Attractive card”
“Very nice Birthday card sturdy”
What buyers complain about
“great card so much bigger than expected ty”
“This card is fairly average in terms of quality and design”
“yes it's pricey”
“The envelope is too dark to write on”
“the design is completely underwhelming”
“No glue on envelope flap”
“it didnt work end up as nice as it looks on the pictures”
“not very sturdy”
“Unfortunately the bracelet broke within the first week”
“Its not thick like a luxury card”
Top return reasons
Common questions
- Is 21st birthday cards for her profitable to sell on Amazon United Kingdom?
- The niche generates £140K/yr across 49 tracked products. 0 of 26 products launched in the last 360 days are still selling. 90-day search growth is -4.6%. Flapen's verdict: Worth a look (54/100).
- How competitive is the 21st birthday cards for her niche?
- 35 brands and 67 sellers compete. The top 5 products take 38% of clicks and top 5 brands hold 43% of demand.
- What do buyers complain about in 21st birthday cards for her?
- Top complaints mined from reviews: Size-Overall, Quality-Overall, Value For Money. The return rate is 0.1%.
- When does demand for 21st birthday cards for her peak?
- Demand is steady year-round — the busiest month runs 1.6× the quietest.
- What does it cost to enter the 21st birthday cards for her niche?
- Listings span £2.10–£11.62; the average listing price is £4.29 (sweet spot $15–$100). The average incumbent carries 373 reviews — the moat a new listing must climb.