Why PPC cannot rescue a listing with no reviews

On Amazon, success is tied to conversion. Amazon gives priority to the product it judges most likely to sell, which is why a new listing has to be set up to convert before anything is spent driving traffic to it.

The problem with advertising an unproven listing

When a listing has low ratings or no reviews, PPC is hard to make work.

In the best case, running advertising produces no positive result and you have simply spent the money.

In the worse case it actively damages the listing. You have shown Amazon that traffic arrived and converted at, say, 3%. Amazon may then read the product as ineffective. After that, even high bids stop buying traffic, because the platform has already formed a view.

That is the part sellers underestimate. Advertising is not neutral when it fails. It is evidence.

Where a product line helps

This is another argument for building a product line rather than a single product.

If you already have one product with a substantial review history, you can configure a new product as a variation of it, and the reviews sit together in one place. The new listing then enters the market with social proof instead of without it.

The practical order

Get the listing to a state where it can convert. Then advertise. Reversing those two steps costs more than the wasted budget, because you also spend the platform's first impression of the product.

To put a number on the review half of that: the rating calculator shows how many reviews at what rating it takes to reach the average you are aiming for, including what happens when a new listing is merged with one that already has a history.