The Advertisers Are the Sellers AgainWide moat
Amazon (AMZN) — moat facet
A toll on top of a toll, levied on merchants who can't decline it — an organic listing nobody sees is not a viable alternative.
Amazon's fourth customer group is mostly its second one. The advertising business took in $76 billion over the twelve months to June 20261, and a large share of it is bought by the same third-party sellers who already pay referral and fulfilment fees — purchasing visibility on a shelf they are already renting.
As a business this is close to perfect. The advertising has no inventory cost, sells against demonstrated purchase intent, and can prove its own effectiveness because Amazon observes the resulting sale. It also has a structural property most ad markets lack: the supply of prominent placements is fixed by the shape of a product page, so as more sellers compete for them, prices rise without Amazon doing anything at all.
The tension is that this is a toll on top of a toll, levied on merchants who mostly cannot decline it — an organic listing that nobody sees is not a viable alternative — and it is a recurring theme in seller complaints and regulatory filings. It also gradually degrades the customer experience that made the shelf valuable, since every promoted result is a result the shopper did not search for. Watch advertising as a share of seller economics, and watch whether search results keep filling with sponsored placements. Both are cases where the profitable direction and the durable one diverge.
A fixed supply of prominent placements against a growing number of bidders raises prices without Amazon doing anything, and the closed-loop attribution keeps advertisers paying. The limit is self-inflicted: every sponsored result degrades the shelf that made the advertising valuable, and sellers' patience is finite.
The second toll, paid mostly by sellers already paying fees. A trailing total that grows faster than seller services, as it has, means the second toll is rising faster than the first.
- Moat Explorer calcThe advertising business took in $76 billion over the twelve months to June 2026, and a large share of it is bought by the same third-party sellers who already pay referral and fulfilment fees — purchasing visibility on a shelf they are already renting.Moat Explorer calculation from Amazon's Form 10-K segment and product-line tables (FY2022-FY2025) and the quarterly results releases: AWS share of operating income = AWS operating income / consolidated operating income ($45,606M / $79,975M = 57.0% in 2025; ($14,161M + $16,621M) / ($23,852M + $27,461M) = 60.0% in H1 2026; $16,621M / $27,461M = 60.5% in Q2 2026; $54,681M / $93,712M = 58.3% TTM); AWS share of net sales $128,725M / $716,924M = 18.0%; retail segments' operating income $29,619M + $4,750M = $34,369M on $588,199M = 5.8%; 2022 segment operating income North America -$2,847M, International -$7,746M, AWS $22,841M against a consolidated $12,248M; North America operating margin -$2,847M / $315,880M = -0.9% in 2022; advertising TTM to June 2026 $17,703M + $21,317M + $17,243M + $19,809M = $76,072M — FY2022-Q2 2026 · publ. 2026 · source ↗Method: Moat Explorer calculation from Amazon's filed segment, product-line and supplemental tables; see the source line for each operand.