When a source changes, you hear first
The Amazon sources of your live listings are watched in two ways. The Seller Library Tracking System checks products about every 12 hours, even with your computer off. With the Chrome extension you can choose 1, 2 or 4 checks a day; for that, the computer and Chrome need to be open.

| Product | Source | Stock | Tracking |
|---|---|---|---|
| Stainless flask | $15.40 | In stock | 12 h · server |
| Silicone spatula | $7.10 ↑ | In stock | 2× a day · extensionBelow margin |
| Bamboo board | — | Unknown | Last check 09:40 |
| Laundry basket | $12.80 | Sold out | 12 h · server |
A value that can't be read isn't guessed · the last real check is kept
- 12 h
- how often the Tracking System checks
- 1 · 2 · 4
- daily checks with the extension
- Unknown
- a value that can't be read isn't guessed
01Steps
How it works

Two ways to track
The Tracking System runs on the server and doesn't wait for your computer to be on. Extension tracking reads from your own browser at the frequency you choose. Both can be used for the same product.
Unknown is a result too
If Amazon doesn't show a page or asks for a verification, no value is guessed. The product is marked 'unknown' and the time of the last real check is kept.
Rises and drops, your choice
You choose in Rules what happens when the source price rises or drops. In Rule mode the price changes between the floor and ceiling you set; a change beyond your limits waits as a suggestion.
Capacity from your package
How many products the Tracking System watches at once is your package's tracking capacity, shown on the Pricing page.
02What changes
The work done by hand is wiped away; one flow takes its place.
- Before
Selling on eBay a product that sold out on AmazonWith SellerLibraryA sold-out source comes as a notification; your rules and approval decide what happens - Before
A margin quietly melting awayWith SellerLibraryA price below your profit target is flagged - Before
Taking a product nobody could check for in stockWith SellerLibraryA price or stock that couldn't be read stays 'unknown', with the last real check's time
03Needs and limits
What to know before you start
What it needs
- Seller Library Tracking System Runs with your computer off, for as many products as your package's tracking capacity.
- Extension tracking The computer and Chrome must be open; 1, 2 or 4 times a day.
Where it stops
- Amazon prices and stock can vary with the US delivery region.
- Reading stops on a page that asks for a verification; there's no attempt to get around it.
- Tracking never deletes an eBay listing on its own.
In the packages
The monthly new-listing allowance, tracking capacity and how many stores you can connect depend on the package. The allowance is shared by all your stores.
See the packages04Ask Selly
About stock and price tracking
Another question? Write to support@sellerlibrary.com or see the FAQ page.

YouDoes tracking work with my computer off?
SellyFor products in the Seller Library Tracking System, yes: they're checked on the server about every 12 hours. Extension tracking needs the computer and Chrome open.
SellyIt means the price or stock couldn't be read reliably in that check. SellerLibrary doesn't guess; the time and value of the last real check are shown separately.
SellyThe Tracking System's capacity depends on your package; each package's tracking capacity is on the Pricing page.
If you're ready, so is Selly.
Applying takes minutes; your invite arrives by email.
