---
title: "Rp19804 — $228K/yr Amazon US Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/us/tools-home-improvement/rp19804"
last_updated: "2026-08-08T16:08:02.725Z"
locale: en
meta:
description: "Niche score 44/100 · $228K/yr market · 76K searches/yr · $24.03 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 44/100 · $228K/yr market · 76K searches/yr · $24.03 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Rp19804 — $228K/yr Amazon US Niche (2026) - Flapen"
---
# **rp19804**
**Skip it**
Brand-locked demand (top 5 brands take 98% of clicks) — this niche doesn't clear our bar today.
Market size 43Growth 25Conversion 95Competition 8Returns 11Price range 95Avg price 95Brand share 5Review moat 81Quality gap 80
**Conversion**
**Incredible****12.4%**
search→purchase rate — share of searches ending in a sale
**Avg price**
**Incredible****$24.03**
avg listing price — sweet spot $15–$100
**Price range**
**Incredible****$14.96–$55.56**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Review moat**
**Great****381.33**
avg incumbent reviews — the moat a new listing must climb
**Quality gap**
**Great****4.2★**
avg incumbent rating — lower means beatable quality
**Market size**
**Okay****$228K**
$228K/yr · 76K searches
**Growth**
**Bad****-0.1%**
90-day search growth — must beat 0% to launch
**Returns**
**Bad****8.8%**
return rate — above 5% kills the launch gate
**Competition**
**Bad****90%**
top-5 click share — a locked-up shelf
**Brand share**
**Bad****98%**
top-5 brand share — brand-locked demand
**Signals**[** Low Review Barrier**](https://flapen.com/research/niches?market=us&signal=low_review_barrier "Top brand's reviews < 500") [** High Returns**](https://flapen.com/research/niches?market=us&signal=high_returns "Return rate > 5%")
According to Flapen's Amazon United States niche tracking, rp19804 is a $228K/yr Amazon United States market (76K searches/yr). The top 5 brands hold 98% of demand. Verdict: Skip it — 44/100.
Data updated Jul 29, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **rp19804 market data**
- **Units sold / yr**
- **10K–13K**
- avg 1,000–1,250/product
- **Revenue / yr**
- **$240K–$300K**
- units × avg price
- **Conversion rate**
- **12.4%**
- **Avg BSR**
- **#119**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **100%**
- **Out of stock**
- **0.0%**
- **Avg brand age**
- **32 months**
- **Avg seller age**
- **155 days**
## **Competition & brand share**
The top 5 products capture 90% of clicks — a locked-up shelf that new listings rarely crack.
**Brands**
**6 **▼falling
**Sellers**
**38**
**Top-5 brand share**
**98%**
Top 20: 100%
**Top-5 click share**
**90%**
Top 20: 100%
**Open market**
**0%**
- Sxtrrdnary42% - DELTA30% - LOWCUS20% - GHAKUTB3% - M Motico2% - Wairool2%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -0.1% search growth over the last 90 days.
2K1KPrime Day '25Spike '25Spike '26 seasonSepDecMarJunAugNovMarMay
No pronounced peak months · busiest ÷ quietest = 1.3×
[**Open Trend **](https://flapen.com/research/us/tools-home-improvement/rp19804/trend)
## **Top rp19804 search terms**
- **rp19804**18K/yr+2.4%10.8% conv. - **delta rp19804**15K/yr+7.2%12.2% conv. - **rp19804 delta shower cartridge**14K/yr-4.6%13.0% conv. - **delta 1400 series cartridge**10K/yr-0.5%8.5% conv. - **delta rp19804 cartridge**7K/yr-9.3%12.9% conv. - **delta 1300/1400 series cartridge**4K/yr+3.5%7.2% conv. - **delta cartridge rp19804**3K/yr+9.4%10.1% conv. - **delta rp19804 replacement cartridge**3K/yr+6.2%13.6% conv. - **delta monitor 1400 series cartridge**3K/yr-17.2%9.7% conv. [**All search terms **](https://flapen.com/research/us/tools-home-improvement/rp19804/search-terms)
## **Top rp19804 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.
0%10%$23K20%$46K30%$68K40%$91K101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 9 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**RP19804 Shower Cartridge Compatible with Delta 1300/1400 Series Single Handle Tub Bathtub Shower Faucet Replacement for Delta Monitor Cartridge Repair Plumbing Parts RP22734 Bonnet Nut (1993-2007)**Sxtrrdnary**$20.90**4.2★345 rev](https://www.amazon.com/dp/B0DH3DRZN8) [2**Delta Faucet RP19804 1300/1400 Series Catridge Assembly Small**DELTA**$55.56**4.5★1,820 rev](https://www.amazon.com/dp/B00JSUKIZU) [3**LOWCUS Shower Cartridge Replacement for Delta RP19804 (04/2006 Earlier) 1-Pack Fits Delta Monitor 1300 1400 Series Single Handle Fix Leak or Drip Temperature or Pressure Issues Includes Bonnet Nut**LOWCUS**$21.45**4.2★251 rev](https://www.amazon.com/dp/B0FQJ7FGNT) [4**LOWCUS Shower Cartridge Replacement for Delta RP19804 (04/2006 Earlier) 1-Pack Fits Delta Monitor 1300 1400 Series Single Handle Fix Leak or Drip Temperature or Pressure Issues Scald Guard**LOWCUS**$19.47**4.2★251 rev](https://www.amazon.com/dp/B0FQC984G5) [5**RP19804 Shower Cartridge Compatible with Delta 1300/1400 Series Single Handle Tub Bathtub Shower Faucet Replacement for Delta Monitor Cartridge Repair Plumbing Parts**Sxtrrdnary**$19.13**4.3★72 rev](https://www.amazon.com/dp/B0DFCGW3WK)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**LOWCUS Shower Cartridge Replacement for Delta RP19804 (04/2006 Earlier) 1-Pack Fits Delta Monitor 1300 1400 Series Single Handle Fix Leak or Drip Temperature or Pressure Issues Includes Bonnet Nut**LOWCUS**$21.45**251 rev10mo ago](https://www.amazon.com/dp/B0FQJ7FGNT) [**LOWCUS Shower Cartridge Replacement for Delta RP19804 (04/2006 Earlier) 1-Pack Fits Delta Monitor 1300 1400 Series Single Handle Fix Leak or Drip Temperature or Pressure Issues Scald Guard**LOWCUS**$19.47**251 rev10mo ago](https://www.amazon.com/dp/B0FQC984G5) [**RP19804 Shower Cartridge Compatible with Delta 1300/1400 Series Single Handle Tub Bathtub Shower Faucet Replacement for Delta Monitor Cartridge Repair Plumbing Parts RP22734 Bonnet Nut (1993-2007)**Sxtrrdnary**$20.90**345 rev1y ago](https://www.amazon.com/dp/B0DH3DRZN8) [**RP19804 Shower Cartridge Compatible with Delta 1300/1400 Series Single Handle Tub Bathtub Shower Faucet Replacement for Delta Monitor Cartridge Repair Plumbing Parts**Sxtrrdnary**$19.13**72 rev1y ago](https://www.amazon.com/dp/B0DFCGW3WK) [**RP19804 Shower Cartridge Assembly Shower Valve Cartridge Replacement for 1300/1400 Series Tub and Shower Pressure Balance Cartridge Compatible with Single-Handle Monitor Shower (1993~2007) 2PCS**M Motico**$27.86**57 rev3y ago](https://www.amazon.com/dp/B0C3TYWND5)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**LOWCUS Shower Cartridge Replacement for Delta RP19804 (04/2006 Earlier) 1-Pack Fits Delta Monitor 1300 1400 Series Single Handle Fix Leak or Drip Temperature or Pressure Issues Scald Guard**LOWCUS**$19.47**4.2★**▲ 68%**](https://www.amazon.com/dp/B0FQC984G5) [**LOWCUS Shower Cartridge Replacement for Delta RP19804 (04/2006 Earlier) 1-Pack Fits Delta Monitor 1300 1400 Series Single Handle Fix Leak or Drip Temperature or Pressure Issues Includes Bonnet Nut**LOWCUS**$21.45**4.2★**▲ 31%**](https://www.amazon.com/dp/B0FQJ7FGNT) [**RP19804 Shower Cartridge Assembly Shower Valve Cartridge Replacement for 1300/1400 Series Tub and Shower Pressure Balance Cartridge Compatible with Single-Handle Monitor Shower (1993~2007) 2PCS**M Motico**$27.86**4.1★**▲ 19%**](https://www.amazon.com/dp/B0C3TYWND5) [**Delta Faucet RP19804 1300/1400 Series Catridge Assembly Small**DELTA**$55.56**4.5★**▲ 17%**](https://www.amazon.com/dp/B00JSUKIZU) [**RP19804 Shower Cartridge Assembly Compatible with Delta Faucet 1300/1400 Series Tub and Shower Valves Replacement Pressure Balance Cartridge For Delta Select Monitor Valves (1993-2007)**GHAKUTB**$15.35**4.2★**— 2%**](https://www.amazon.com/dp/B0C1JSV4TY)
**~~View all trending →~~**
## **What buyers say about rp19804**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**22%
*“Fit perfect”*
**Leak-Proof**18%
*“It fits and doesn't leak”*
**Value For Money**15%
*“Good deal”*
**Assembly/Installation**13%
*“Easy enough to install”*
**Quality-Overall**9%
*“Quality cartridge”*
**Advertised Vs Actual Product**5%
*“works as advertised”*
**Efficiency**3%
*“Works great”*
**Ease Of Use**2%
*“Easy Peezy”*
**Pressure**2%
*“Water pressure is better than its been in years”*
**Durability**1%
*“It does feel durable”*
### **What buyers complain about **
**Size-Overall**23%
*“of this product is too big”*
**Leak-Proof**15%
*“Started leaking quickly and made a big mess”*
**Durability**7%
*“Easily broken”*
**Value For Money**7%
*“Although it is quite expensive for what it is”*
**Assembly/Installation**7%
*“could not install”*
**Functionality-Overall**4%
*“It didnt work for me”*
**Quality-Overall**4%
*“Poorly quality, does not fit”*
**Compatibility-Overall**3%
*“It did not fit my pre 2006 RP 19804”*
**Product Condition**3%
*“Return resold”*
**Defective Material/Parts**2%
*“This part is junk”*
### **Top return reasons **
**Size-Overall**57%
**Compatibility-Overall**19%
**Defective Material/Parts**5%
**Leak-Proof**4%
**Assembly/Installation**4%
**Functionality-Overall**3%
**Advertised Vs Actual Product**3%
**Product Condition**2%
**Value For Money**1%
**Maintenance And Repair**1%
## **Common questions**
- **Is rp19804 profitable to sell on Amazon United States?**
- The niche generates $228K/yr across 9 tracked products. 2 of 2 products launched in the last 360 days are still selling. 90-day search growth is -0.1%. Flapen's verdict: Skip it (44/100).
- **How competitive is the rp19804 niche?**
- 6 brands and 38 sellers compete. The top 5 products take 90% of clicks and top 5 brands hold 98% of demand.
- **What do buyers complain about in rp19804?**
- Top complaints mined from reviews: Size-Overall, Leak-Proof, Durability. The return rate is 8.8% — above our launch gate.
- **When does demand for rp19804 peak?**
- Demand is steady year-round — the busiest month runs 1.3× the quietest.
- **What does it cost to enter the rp19804 niche?**
- Listings span $14.96–$55.56; the average listing price is $24.03 (sweet spot $15–$100). The average incumbent carries 381 reviews — the moat a new listing must climb.
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