---
title: "Monofin — $11K/mo Amazon US Product Research (2026)"
canonical_url: "https://flapen.com/research/us/sports-outdoors/monofin"
last_updated: "2026-08-12T11:21:04.421Z"
locale: en
meta:
description: "Amazon product research for monofin: $11K/mo market, demand, competition, pricing, reviews & the verdict. Know if it's worth selling — Flapen."
"og:description": "Amazon product research for monofin: $11K/mo market, demand, competition, pricing, reviews & the verdict. Know if it's worth selling — Flapen."
"og:title": "Monofin — $11K/mo Amazon US Product Research (2026)"
---
# **Monofin**
**Worth a look**
Shows demand growing +170.8% this quarter, but weak search conversion (1.6%) keeps it on the watch list.
Market size 29Growth 97Conversion 19Competition 79Returns 35Price range 38Avg price 91Brand share 30Review moat 58Quality gap 47
**Growth**
**Incredible****+170.8%**
90-day search growth — must beat 0% to launch
**Avg price**
**Great****$54.64**
avg listing price — sweet spot $15–$100
**Competition**
**Great****36%**
top-5 click share — an open shelf
**Review moat**
**Good****1,180.82**
avg incumbent reviews — the moat a new listing must climb
**Quality gap**
**Okay****4.5★**
avg incumbent rating — lower means beatable quality
**Price range**
**Okay****$5.98–$228.28**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Returns**
**Okay****4.2%**
return rate — above 5% kills the launch gate
**Brand share**
**Okay****87%**
top-5 brand share — brands hold most of the demand
**Market size**
**Okay****$127K**
$127K/yr · 150K searches
**Conversion**
**Bad****1.6%**
search→purchase rate — share of searches ending in a sale
**Signals**[** Trending**](https://flapen.com/research/niches?market=us&signal=trending "Search growth > 100% (90d)") [** High Price**](https://flapen.com/research/niches?market=us&signal=high_price "Avg price > $50")
## **Is monofin profitable on Amazon?**
According to Flapen's Amazon United States niche tracking, monofin is a $127K/yr Amazon United States market (150K searches/yr). The top 5 brands hold 87% of demand. Demand peaks in Jun–Jul–Aug. Verdict: Worth a look — 53/100.
Data updated Jul 26, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **monofin market size & sales**
Units sold, revenue, conversion and listing quality across the tracked shelf.
- **Units sold / yr**
- **2K–3K**
- avg 0–100/product
- **Revenue / yr**
- **$109K–$137K**
- units × avg price
- **Conversion rate**
- **1.6%**
- **Avg BSR**
- **#1,556**
- **Page quality**
- **0%**
- **Prime**
- **75%**
- **Sponsored**
- **78%**
- **Out of stock**
- **2.5%**
- **Avg brand age**
- **49 months**
- **Avg seller age**
- **174 days**
## **Competition: brands, sellers & click share**
Clicks spread well past the top 5 (36% combined) — an open shelf where new products get seen.
**Brands**
**14 **▲rising
**Sellers**
**21**
**Top-5 brand share**
**87%**
Top 20: 100%
**Top-5 click share**
**36%**
Top 20: 78%
**Open market**
**10%**
- Fin Fun30% - Body Glove23% - Sun Tails19% - FINIS7% - Foyinbet7% - AIWANK3% - Open — no brand owns it (8 brands, 10%)
## **monofin demand & seasonality**
Weekly Amazon search volume, last 104 weeks — +170.8% search growth over the last 90 days.
8K6KHoliday '24Spike '25Prime Day '25Black Friday '25Holiday '25Spike '26Prime Day '26 seasonSepDecMarJunAugNovMarMay
Peak months: Jun, Jul, Aug · busiest ÷ quietest = 6.1×
[**Open Trend **](https://flapen.com/research/us/sports-outdoors/monofin/trend)
## **Top monofin search terms shoppers use**
The exact queries shoppers type, with yearly volume, growth and conversion.
- **monofin**50K/yr+168.3%0.9% conv. - **monofin adult**18K/yr+212.0%1.2% conv. - **mermaid fin**17K/yr+141.0%1.4% conv. - **mermaid fins for girls**11K/yr+108.1%1.8% conv. - **mono fin**6K/yr+146.2%0.7% conv. - **adult monofin**5K/yr+258.8%1.7% conv. - **monofin for kids**6K/yr+246.8%2.2% conv. - **mermaid monofin**6K/yr+175.0%1.1% conv. - **mermaid fins**7K/yr+112.9%1.0% conv. - **mermaid fin for swimming**7K/yr+125.0%1.4% conv. [**All search terms **](https://flapen.com/research/us/sports-outdoors/monofin/search-terms)
## **Top monofin products & what they sell for**
Every tracked product — its share of the shelf, its review moat, and what it sells for.
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%3%$4K6%$8K9%$11K12%$15K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 24 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**Mermaid Linden Kids Monofin - Pink**Body Glove**$42.59**4.6★2,608 rev](https://www.amazon.com/dp/B00YBYAQZK) [2**Fin Fun Mermaid Monofin Swim Fin for Kids and Adults (Blue Trim Black Junior - Ages 6-11)**Fin Fun**$33.33**4.6★3,347 rev](https://www.amazon.com/dp/B07482KCXB) [3**Mermaid Linden Kids Monofin-Blue**Body Glove**$38.86**4.6★2,608 rev](https://www.amazon.com/dp/B00YBYAI12) [4**Fin Fun Mermaid Monofin - Swim Fin for Kids & Adults Ages 12 and Up - Swimming Flipper with Comfortable Foot Pockets - Snorkel & Water Accessory Made w/ Dive-Grade Neoprene - (Blue Trim Black Pro)**Fin Fun**$38.67**4.6★3,347 rev](https://www.amazon.com/dp/B074839XGF) [5**Sun Tails Mermaid Monofin (Turquoise Nunui - Teen/Adult Size)**Sun Tails**$49.02**4.4★381 rev](https://www.amazon.com/dp/B01IC6FMPQ)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**Fin Fun Mermaid Monofin - Swim Fin for Kids Ages 6-11 - Swimming Flipper with Comfortable Foot Pockets - Snorkel & Water Accessory Made w/ Dive-Grade Neoprene - JR Small**Fin Fun**$34.04**3,347 rev5mo ago](https://www.amazon.com/dp/B0GQ9T6Q2K) [**Fin Fun Mermaid Monofin - Swim Fin for Kids & Adults Ages 12 and Up - Swimming Flipper with Comfortable Foot Pockets - Snorkel & Water Accessory Made w/ Dive-Grade Neoprene - Pro Small**Fin Fun**$39.08**3,347 rev5mo ago](https://www.amazon.com/dp/B0GQ9JC2N3) [**Fin Fun Asian Magenta Mermaid Tail with Monofin Women & Teens XS**Fin Fun**$73.14**19 rev5mo ago](https://www.amazon.com/dp/B0GLCX5W69) [**Mermaid Linden Adult Monofin - BLK/SIL**Body Glove**$69.47**24 rev12mo ago](https://www.amazon.com/dp/B0FKFG2R96) [**Mermaid Linden Adult Monofin - Ultramarine Purple**Body Glove**$69.50**14 rev12mo ago](https://www.amazon.com/dp/B0FKFF8X35)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**Fin Fun Mermaid Monofin - Swim Fin for Kids Ages 6-11 - Swimming Flipper with Comfortable Foot Pockets - Snorkel & Water Accessory Made w/ Dive-Grade Neoprene - JR Small**Fin Fun**$34.04**4.6★**▲ 32%**](https://www.amazon.com/dp/B0GQ9T6Q2K) [**Fin Fun Mermaid Monofin - Swim Fin for Kids & Adults Ages 12 and Up - Swimming Flipper with Comfortable Foot Pockets - Snorkel & Water Accessory Made w/ Dive-Grade Neoprene - Pro Small**Fin Fun**$39.08**4.6★**▲ 32%**](https://www.amazon.com/dp/B0GQ9JC2N3) [**Mermaid Tail and Monofin for Swimming with MER-Shield Tip Protection Adult Sizes (Bali Blush - Purple Monofin Adult L (JL 12-16))**Sun Tails**$79.91**4.5★**▲ 31%**](https://www.amazon.com/dp/B087RSJDPS) [**Foyinbet Kids Swim Fins Short Kids Fins Youth Swimming Flippers for Lap Swimming Training for Children Girls Boys Beginners 2XS**Foyinbet**$27.73**4.6★**▲ 30%**](https://www.amazon.com/dp/B09TW6WKBK) [**Sun Tails Mermaid Monofin (Green Keiki - Child Size)**Sun Tails**$44.33**4.4★**▲ 29%**](https://www.amazon.com/dp/B01IC6FMEC)
**~~View all trending →~~**
## **What reviews say buyers love and hate about monofin**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**18%
*“Fits PERFECTLY”*
**Quality-Overall**11%
*“Great build quality”*
**Value For Money**11%
*“Definitely worth the cost”*
**Comfort-Overall**10%
*“It is comfortable”*
**Advertised Vs Actual Product**10%
*“Exactly as described”*
**Fun/Entertainment Experience**8%
*“My child was heartbroken because it is such a fun monofin”*
**Durability**6%
*“It is very durable”*
**Water Resistance**4%
*“has great propulsion in the water”*
**Ease Of Use**3%
*“can easily use these”*
**Weight Light**2%
*“lightweight blanket”*
### **What buyers complain about **
**Size-Overall**53%
*“Tight”*
**Strap/String Quality**6%
*“The 1st one the snaps and straps broke”*
**Durability**4%
*“Broke after a few uses”*
**Comfort-Overall**4%
*“Lowkey dangerous & also uncomfortable hehe”*
**Weight Heavy**4%
*“Too heavy”*
**Ease Of Use**2%
*“its hard to get on quickly”*
**Pain Relief-Overall**2%
*“hurts to put on”*
**Functionality-Overall**2%
*“Does not work”*
**Measurement/Reading Accuracy**2%
*“I do not see how that can be accurate”*
**Advertised Vs Actual Product**2%
*“Maybe this should not be advertised for small children”*
### **Top return reasons **
**Size-Overall**80%
**Advertised Vs Actual Product**3%
**Functionality-Overall**3%
**Strap/String Quality**2%
**Color**1%
**Value For Money**1%
**Comfort-Overall**1%
**Quality-Overall**1%
**Defective Material/Parts**1%
**Material Quality**1%
## **Common monofin questions**
- **Is monofin profitable to sell on Amazon United States?**
- The niche generates $127K/yr across 51 tracked products. 8 of 10 products launched in the last 360 days are still selling. 90-day search growth is +170.8%. Flapen's verdict: Worth a look (53/100).
- **How competitive is the monofin niche?**
- 14 brands and 21 sellers compete. The top 5 products take 36% of clicks and top 5 brands hold 87% of demand.
- **What do buyers complain about in monofin?**
- Top complaints mined from reviews: Size-Overall, Strap/String Quality, Durability. The return rate is 4.2%.
- **When does demand for monofin peak?**
- Demand peaks in Jun–Jul–Aug; the busiest month runs 6.1× the quietest.
- **What does it cost to enter the monofin niche?**
- Listings span $5.98–$228.28; the average listing price is $54.64 (sweet spot $15–$100). The average incumbent carries 1,181 reviews — the moat a new listing must climb.
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