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March 19, 2026Ad ServerNew Feature

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The Problem

Banner ad slots don’t always have Topsort demand. When no vendor campaigns target a given placement, the slot goes unfilled and the marketplace earns nothing from that impression, leaving revenue on the table.

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The Solution

Demand fallback integrates Google Ad Manager (GAM) into the Topsort auction flow for enabled banner ad slots. When the auction endpoint has no Topsort demand for a banner request, it returns a GAM tag (a snippet of JavaScript) instead of an empty result. The marketplace renders the tag, which displays a programmatic banner ad from GAM, earning incremental revenue from otherwise unfilled inventory. No wasted impressions. Banner slots that would have gone unfilled now generate revenue through GAM open auction or direct deals. Same auction endpoint. No new API integration required. The existing auctions endpoint returns the GAM tag in the winner’s asset field when fallback is triggered. Topsort-managed configuration. Topsort handles the GAM setup, placement mapping, and passback tag generation. The marketplace only needs to render the returned tag.

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How It Works

1

Auction request

The marketplace sends a banner auction request to the Topsort auction endpoint as usual.
2

No Topsort demand

If no Topsort campaigns bid on the slot, the auction falls back to GAM demand.
3

GAM tag returned

The auction response includes a GAM snippet in the winner’s asset array. The content field contains a string containing a GAM passback tag to render the GAM ad.
4

Marketplace renders the tag

The marketplace parses the GAM snippet from the response and renders it on the page, displaying a programmatic banner ad.
Available now for eligible marketplaces. Integration typically takes 3–4 weeks. Contact your Topsort account team to get started, or see the Third Party Demand documentation for full details.