tdcs
Skip itA small market ($8K/yr) — this niche doesn't clear our bar today.
Quality gap
Great4.3★avg incumbent rating — lower means beatable quality
Avg price
Good$140.07avg listing price — sweet spot $15–$100
Returns
Okay4.7%return rate — above 5% kills the launch gate
Price range
Okay$33.62–$266.80cheapest to priciest tracked listing — scored on the share inside $15–$100
Review moat
Bad12,468.86avg incumbent reviews — the moat a new listing must climb
Growth
Bad-12.4%90-day search growth — must beat 0% to launch
Brand share
Bad94%top-5 brand share — brand-locked demand
Competition
Bad94%top-5 click share — a locked-up shelf
Market size
Bad$8K$8K/yr · 39K searches
Conversion
Bad0.1%search→purchase rate — share of searches ending in a sale
According to Flapen's Amazon United States niche tracking, tdcs is a $8K/yr Amazon United States market (39K searches/yr). The top 5 brands hold 94% of demand. Verdict: Skip it — 22/100.
Data updated Jul 14, 2026 · scored weekly · How we score niches
tdcs market data
- Units sold / yr
- 100–250
- avg 0–100/product
- Revenue / yr
- $14K–$35K
- units × avg price
- Conversion rate
- 0.1%
- Avg BSR
- #2,142
- Page quality
- 0%
- Prime
- 100%
- Sponsored
- 86%
- Out of stock
- 3.5%
- Avg brand age
- 52 months
- Avg seller age
- 164 days
Competition & brand share
The top 5 products capture 94% of clicks — a locked-up shelf that new listings rarely crack.Brands
7 falling
Sellers
32
Top-5 brand share
94%
Top 20: 100%
Top-5 click share
94%
Top 20: 100%
Open market
3%
- AliveCor42%
- SereniBrain19%
- Garmin16%
- Balego9%
- Pulsetto6%
- MagnetRX3%
- Open — no brand owns it (1 brand, 3%)
Demand & seasonality
Weekly Amazon search volume, last 104 weeks — -12.4% search growth over the last 90 days.No pronounced peak months · busiest ÷ quietest = 1.4×
Top tdcs search terms
- transcranial magnetic stimulation device10K/yr
- tdcs brain stimulator9K/yr
- transcranial magnetic stimulation6K/yr
- tdcs device5K/yr
- neuromyst2K/yr
Top tdcs 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 7 tracked products in this niche — three views at once, no toggling.
Top sellers
by 90-day click share
KardiaMobile 1-Lead EKG Monitor Medical-Grade FDA-Cleared Personal Heart Monitor Detects Normal AFib & Arrhythmias 30 Second Results Works with Most Smartphones HSA&FSA Eligible
AliveCor$73.894.4★83,279 rev
SereniBrain EEG Neurofeedback Headband for Meditation & Brainwave Monitoring Real-Time Brain Activity Tracker with App Train Focus Relaxation & Sleep Preparation
SereniBrain$184.674.0★98 rev
Garmin HRM 600 Premium Heart Rate Monitor Accurate Heart Rate and HRV Data Running Dynamics Stand-Alone Activity Recording M-XL
Garmin$167.904.6★1,073 rev
Balego EMS Digital Neuromuscular NMES Stimulator OTC
Balego$61.754.4★2,273 rev
Pulsetto FIT (V2) Wellness Wearable Relaxation Sleep & Daily Wellness Support Device
Pulsetto$266.803.9★464 rev
Newest
by launch datePulsetto FIT (V2) Wellness Wearable Relaxation Sleep & Daily Wellness Support Device
Pulsetto$266.80464 rev
Garmin HRM 600 Premium Heart Rate Monitor Accurate Heart Rate and HRV Data Running Dynamics Stand-Alone Activity Recording M-XL
Garmin$167.901,073 rev
B-Pulse Bilateral Stimulation Tool Dual Vibration Units with Adjustable Straps EMDR Therapy Device for Children and Adults
B-pulse$191.9149 rev
SereniBrain EEG Neurofeedback Headband for Meditation & Brainwave Monitoring Real-Time Brain Activity Tracker with App Train Focus Relaxation & Sleep Preparation
SereniBrain$184.6798 rev
MagnetRX Magnetic Therapy Massage Fork MultiFunctional Magnetotherapy Pen for Emotion Code Magnets Meridian Massage Tool & Body Healing Magnets Magnetoterapia Fisioterapia Portatil Aparatos
MagnetRX$33.6246 rev
Trending
90-day click momentumKardiaMobile 1-Lead EKG Monitor Medical-Grade FDA-Cleared Personal Heart Monitor Detects Normal AFib & Arrhythmias 30 Second Results Works with Most Smartphones HSA&FSA Eligible
AliveCor$73.894.4★
Garmin HRM 600 Premium Heart Rate Monitor Accurate Heart Rate and HRV Data Running Dynamics Stand-Alone Activity Recording M-XL
Garmin$167.904.6★
Pulsetto FIT (V2) Wellness Wearable Relaxation Sleep & Daily Wellness Support Device
Pulsetto$266.803.9★
SereniBrain EEG Neurofeedback Headband for Meditation & Brainwave Monitoring Real-Time Brain Activity Tracker with App Train Focus Relaxation & Sleep Preparation
SereniBrain$184.674.0★
Balego EMS Digital Neuromuscular NMES Stimulator OTC
Balego$61.754.4★
What buyers say about tdcs
What buyers praise and complain about, mined from review topics.What buyers love
“The device is easy to use”
“Excellent Product”
“It's comfortable and feels good”
“As advertised”
“Very effective”
“great value”
“The app is also very well done”
“Battery life is excellent”
“Pairing with your phone is straightforward”
“The fit is comfortable”
What buyers complain about
“For me, no results”
“For this price it is a total scam”
“APP SCAM”
“it keeps disconnecting”
“Difficult to use”
“This broke the first day I got it”
“Cheap product”
“Deceiving”
“no way to recharge”
“Compatibility Problems”
Top return reasons
Common questions
- Is tdcs profitable to sell on Amazon United States?
- The niche generates $8K/yr across 7 tracked products. 90-day search growth is -12.4%. Flapen's verdict: Skip it (22/100).
- How competitive is the tdcs niche?
- 7 brands and 32 sellers compete. The top 5 products take 94% of clicks and top 5 brands hold 94% of demand.
- What do buyers complain about in tdcs?
- Top complaints mined from reviews: Functionality-Overall, Value For Money, Software/Application. The return rate is 4.7%.
- When does demand for tdcs peak?
- Demand is steady year-round — the busiest month runs 1.4× the quietest.
- What does it cost to enter the tdcs niche?
- Listings span $33.62–$266.80; the average listing price is $140.07 (sweet spot $15–$100). The average incumbent carries 12,469 reviews — the moat a new listing must climb.