4 inch memory foam mattress topper king
Worth a lookShows no brand lock-in (top 5 brands take 44% of clicks), but a failed launch gate (market size, growth, or returns) keeps it on the watch list.
Brand share
Great44%top-5 brand share — no brand owns this niche
Competition
Great31%top-5 click share — an open shelf
Quality gap
Great4.2★avg incumbent rating — lower means beatable quality
Avg price
Good$103.95avg listing price — sweet spot $15–$100
Returns
Good2.6%return rate — above 5% kills the launch gate
Conversion
Good4.6%search→purchase rate — share of searches ending in a sale
Market size
Okay$209K$209K/yr · 44K searches
Price range
Okay$41.50–$207.08cheapest to priciest tracked listing — scored on the share inside $15–$100
Review moat
Bad8,135.75avg incumbent reviews — the moat a new listing must climb
Growth
Bad-21.2%90-day search growth — must beat 0% to launch
According to Flapen's Amazon United States niche tracking, 4 inch memory foam mattress topper king is a $209K/yr Amazon United States market (44K searches/yr). The top 5 brands hold 44% of demand. Demand peaks in Sep. Verdict: Worth a look — 56/100.
Data updated Jul 29, 2026 · scored weekly · How we score niches
4 inch memory foam mattress topper king market data
- Units sold / yr
- 1K–2K
- avg 0–100/product
- Revenue / yr
- $130K–$156K
- units × avg price
- Conversion rate
- 4.6%
- Avg BSR
- #145
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 92%
- Out of stock
- 19.4%
- Avg brand age
- 33 months
- Avg seller age
- 185 days
Competition & brand share
Clicks spread well past the top 5 (31% combined) — an open shelf where new products get seen.Brands
35 falling
Sellers
31
Top-5 brand share
44%
Top 20: 86%
Top-5 click share
31%
Top 20: 66%
Open market
50%
- WhatsBedding13%
- Sweetcrispy11%
- Niagara Sleep Solution7%
- BEDLORE7%
- MASVIS6%
- COONP5%
Demand & seasonality
Weekly Amazon search volume, last 102 weeks — -21.2% search growth over the last 90 days.Peak months: Sep · busiest ÷ quietest = 1.6×
Top 4 inch memory foam mattress topper king search terms
- 4 inch memory foam mattress topper king23K/yr
- 4 inch king mattress topper11K/yr
- king size down mattress topper10K/yr
Top 4 inch memory foam mattress topper king 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
Sweetcrispy Mattress Topper King Memory Foam 4 Inch Cooling Pad
Sweetcrispy$71.044.0★186 rev
MASVIS King Size Dual Layer 4 Inch Memory Foam Mattress Topper 2 Inch Gel Memory Foam and 2 Inch Cooling Pillow Top Mattress Pad Cover for Back Pain Medium Support
MASVIS$112.604.3★5,499 rev
COONP King Mattress Topper Extra Thick Pillowtop Cooling Plush Mattress Pad Cover Cotton Top Bed Topper Protector with 8-21 Inch Deep Pocket
COONP$77.304.4★34,535 rev
BEDLORE King Mattress Topper Viscose Derived from Bamboo Thick Pillow Top Mattress Pad with Stretchable Pockets for 6-18 Mattress Soft Breathable Mattress Topper for Back Pain Relief(Dark Gray)
BEDLORE$53.284.4★12,633 rev
WhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Filled with Fluffy Gel Memory Foam Soft and Thick Supportive Mattress Topper 4 Stable Anchor Elastic Straps
WhatsBedding$78.973.6★22 rev
Newest
by launch dateWhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Relief Filled with Breathable Gel Memory Foam Supportive Pillow Top Mattress Topper
WhatsBedding$139.4619 rev
IULULU Mattress Topper King Size 4 Inch Gel Memory Foam Bed Topper
IULULU$66.679,570 rev
WhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Relief
WhatsBedding$149.422 rev
Missleep Dual Layer 4 Inch Memory Foam Mattress Topper King Size 2 Inch Cooling Gel Memory Foam 2 Inch Soft Pillow Top Pad Breathable Mattress Cover for Back Pain Relief Deep Elastic Pocket White
Missleep$119.5729 rev
WhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Filled with Fluffy Gel Memory Foam Soft and Thick Supportive Mattress Topper 4 Stable Anchor Elastic Straps
WhatsBedding$78.9722 rev
Trending
90-day click momentumWhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Relief
WhatsBedding$149.423.6★
Missleep Dual Layer 4 Inch Memory Foam Mattress Topper King Size 2 Inch Cooling Gel Memory Foam 2 Inch Soft Pillow Top Pad Breathable Mattress Cover for Back Pain Relief Deep Elastic Pocket White
Missleep$119.574.0★
WhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Relief Filled with Breathable Gel Memory Foam Supportive Pillow Top Mattress Topper
WhatsBedding$139.465.0★
WhatsBedding 4 Inch Memory Foam Mattress Topper King for Back Pain Filled with Fluffy Gel Memory Foam Soft and Thick Supportive Mattress Topper 4 Stable Anchor Elastic Straps
WhatsBedding$78.973.6★
IULULU Mattress Topper King Size 4 Inch Gel Memory Foam Bed Topper
IULULU$66.674.4★
What buyers say about 4 inch memory foam mattress topper king
What buyers praise and complain about, mined from review topics.What buyers love
“comfortable to use”
“Extremely soft”
“Good product, as expected”
“Very affordable”
“Perfect mattress topper”
“Amazing sleep”
“Fit great”
“As advertised”
“Extra cushion”
“Thickness was as reported”
What buyers complain about
“Not as thick as you think”
“False Advertising”
“Not as comfortable as seems”
“Not enough cushion”
“Don't expect too much at this price point”
“Not as fluffy”
“Doesnt fit properly”
“Extremely poor quality”
“Hard as a rock”
“Chemical Smell”
Top return reasons
Common questions
- Is 4 inch memory foam mattress topper king profitable to sell on Amazon United States?
- The niche generates $209K/yr across 59 tracked products. 18 of 29 products launched in the last 360 days are still selling. 90-day search growth is -21.2%. Flapen's verdict: Worth a look (56/100).
- How competitive is the 4 inch memory foam mattress topper king niche?
- 35 brands and 31 sellers compete. The top 5 products take 31% of clicks and top 5 brands hold 44% of demand.
- What do buyers complain about in 4 inch memory foam mattress topper king?
- Top complaints mined from reviews: Thickness, Advertised Vs Actual Product, Comfort-Overall. The return rate is 2.6%.
- When does demand for 4 inch memory foam mattress topper king peak?
- Demand peaks in Sep; the busiest month runs 1.6× the quietest.
- What does it cost to enter the 4 inch memory foam mattress topper king niche?
- Listings span $41.50–$207.08; the average listing price is $103.95 (sweet spot $15–$100). The average incumbent carries 8,136 reviews — the moat a new listing must climb.