eBay to Amazon alerts: how to get told only about listings that clear your profit line

Short answer

Pick a short list of products you know. Write down the profit line each one must clear. Watch new eBay listings for those products only, run the fee math on every match, and send yourself a message only when the math passes. Everything else in this guide is detail on one of those four moves.

Step 1: choose the products to watch

Start with products you already sell or have researched, and keep the list short. A list of 20 you know well produces alerts you can judge at a glance. A list of 500 you barely know produces alerts you cannot judge at all.

• Write the Amazon ASIN, the manufacturer model number and the form you sell (bare, kit, single, multipack).
• Note the usual ways an eBay title gets this product wrong, such as a missing suffix or a kit described as a bare item.
• Drop any product you are not approved to sell in the condition you would buy it.

The method works best on products with a clean model number, because that number is what lets a machine, or you, match a listing to one Amazon item. Our guide to screening power tools shows the same idea applied to one category.

Step 2: set the profit line before any listing exists

Decide two numbers per product: the minimum profit in dollars and the minimum return on what you spend. Decide them now, while you are calm, not while a listing is ticking down. Here is a worked example with invented numbers.

Invented example, US dollars

Amazon sale price        80.00
- referral fee (15%)     12.00
- fulfillment fee         5.50
= Amazon proceeds        62.50

eBay asking price        41.00
+ eBay shipping to you    6.00
+ prep and inbound        2.00
= your total cost        49.00

profit  = 62.50 - 49.00 = 13.50
return  = 13.50 / 49.00 = 27.6%

If your line for this product is a minimum profit of 10.00 and a minimum return of 20%, this listing clears it. If the seller asked 46.00 instead, profit falls to 8.50 and return to 15.5%, and it does not. The 15% referral fee is an example only. Use Amazon's own fee preview for your exact item and category.

Two things move the line more than people expect: shipping you pay on the eBay side, and sales tax if you pay it. Put both in the cost before you compare.

Step 3: choose how the alert reaches you

An alert you do not see is not an alert. Pick the channel you actually look at.

• eBay saved searches send email when new matching items are listed. They are free and built in, but they work from keywords and show no Amazon price or profit. See eBay saved searches compared for what eBay's own help page says.
• A spreadsheet you check on a rhythm has no alerts at all. It depends on your attention, and it works if you set a schedule.
• Telegram messages arrive as push notifications on your phone. This is the channel MarginPing uses.

Whatever you choose, do not promise yourself a delivery time. Email and messaging apps both vary, and a listing can still be gone before you open the message. Look for a tool that shows when the listing appeared and when the alert was sent, so you can judge the gap yourself.

Step 4: match every listing before you trust the numbers

The fee math is only as good as the match. Before you act on any alert, check these in the listing itself:

1. The model number in the title or item details matches your product, suffix included.
2. The form matches: bare tool or kit, single or lot, new or used.
3. The photos show the item described, with the parts the Amazon listing includes.
4. The condition words fit a condition you may sell. “For parts”, “untested” and “open box” need extra care.

A wrong match is the most common way an alert that looks good turns into a loss. Our step-by-step sourcing guide covers matching and records in more depth.

Step 5: tune the noise every week

After the first week you will see which products produce alerts and which never do. Keep a column in your sheet for what you did with each alert and why.

• If a product alerts often but you always skip it, tighten the line or fix the match rule.
• If a product never alerts, check that your Amazon price is current and that the line is not set above anything eBay sellers ask.
• If you wished you had bought a second unit, note that product and watch it more closely.

Refresh your Amazon prices on a schedule. A profit line checked against a price from last month will fire on listings that no longer clear it, or stay silent on ones that do.

Where software takes over

Steps 2 to 4 repeat for every new listing. MarginPing does that repetition for power tools and tool kits you already sell. You give it your list. It watches new eBay listings for those products, matches by the model number in the eBay title and by UPC when the listing has one, reads kit versus bare tool and lot size, and shows a match confidence score. It works out estimated Amazon fees and profit, and sends a Telegram message only when the profit clears the line you set.

Amazon prices and fee estimates refresh several times a day. You do not need to connect an Amazon account to use it. Each alert shows when the listing appeared and when it was sent, and we do not promise a delivery time. It never buys, bids, or messages a seller, so Step 4 and the purchase stay with you.

MarginPing is in final testing and not open for signups yet. At launch: $100 a month for up to 20 products. Starts with a free 7-day trial, no card needed, when we open. See power tools for what an alert shows, or how to find eBay listings to flip on Amazon if you are still choosing what to watch.

Questions