Overview

Amazon’s advertising team now advises sellers to use the “dynamic bids – down only” option for Sponsored Products when introducing brand‑new ASINs during the back‑to‑school rush. The guidance is based on internal data that shows higher return on ad spend (ROAS), more clicks and more orders compared to the default “up and down” setting. Sellers targeting school‑related categories should consider the recommendation to keep launch costs under control while still reaching shoppers ready to buy.

Key Points

• Dynamic “down only” bidding for fresh ASINs — Amazon suggests the conservative bid mode for products that lack a conversion track record.
• 18 % lift in ROAS — Campaigns that applied down‑only bidding generated roughly one‑eighth more revenue per advertising dollar than those using up‑and‑down bidding.
• 7.4 % increase in clicks — Advertisers saw a modest but measurable rise in click volume, indicating better ad visibility to interested shoppers.
• 6.2 % boost in orders — The same campaigns delivered more ad‑attributed sales, confirming that the extra clicks translated into purchases.
• Back‑to‑school focus — The recommendation targets sellers in stationery, backpacks, sports apparel, electronics, dorm supplies and other school‑season categories.

How Dynamic “Down Only” Bidding Works

1. Bid ceiling set by the seller — You define a maximum cost‑per‑click (CPC) for each keyword or product target. For example, a seller launching a new ergonomic backpack may set a base bid of $1.20.
2. Amazon lowers bids when conversion likelihood drops — The algorithm automatically reduces the CPC for impressions that appear unlikely to convert, such as a shopper browsing low‑priced accessories unrelated to school gear.
3. No upward adjustments — Unlike the “up and down” mode, the system never raises the bid above the ceiling you entered, protecting you from overspending on unproven placements.

Context: Before vs. After

• : A seller launching a new set of reusable water bottles used the default “up and down” setting. The algorithm increased bids on high‑traffic placements, resulting in a $2,500 spend in the first week but only $1,800 in sales, yielding a ROAS of 0.72.