increase the ad limit on fronts to measure impact

ab-testing/config/abTests.ts

@@ -69,6 +69,19 @@ const ABTests: ABTest[] = [
 		groups: ["holdback"],
 		shouldForceMetricsCollection: true,
 	},
+	{
+		name: "commercial-fronts-ad-increase-ad-limit",
+		description:
+			"A test to understand the impact of changing page-level ad limit on fronts",
+		owners: ["commercial.dev@guardian.co.uk"],
+		expirationDate: "2026-08-11",
+		type: "client",
+		status: "ON",
+		audienceSize: 10 / 100,
+		audienceSpace: "A",
+		groups: ["control", "variant"],
+		shouldForceMetricsCollection: true,
+	},
 	{
 		name: "newsletters-in-article-signup-preview",
 		description:

dotcom-rendering/src/layouts/FrontLayout.tsx

@@ -31,6 +31,7 @@ import { SubNav } from '../components/SubNav.island';
 import { TrendingTopics } from '../components/TrendingTopics';
 import { ArticleDisplay } from '../lib/articleFormat';
 import { canRenderAds } from '../lib/canRenderAds';
+import { getMaxFrontsBannerAds } from '../lib/commercial-constants';
 import { getContributionsServiceUrl } from '../lib/contributions';
 import { editionList } from '../lib/edition';
 import {
@@ -40,6 +41,7 @@ import {
 } from '../lib/getFrontsAdPositions';
 import { hideAge } from '../lib/hideAge';
 import { ophanComponentId } from '../lib/ophan-helpers';
+import { useAB } from '../lib/useAB';
 import { worldCup2026PageIds } from '../lib/worldCup2026';
 import type { NavType } from '../model/extract-nav';
 import { palette as schemePalette } from '../palette';
@@ -117,6 +119,10 @@ export const FrontLayout = ({ front, NAV }: Props) => {
 		editionId,
 	} = front;
 
+	const abTests = useAB();
+
+	const maxAds = getMaxFrontsBannerAds(abTests);
+
 	const serverTime = front.serverTime;
 
 	const renderAds = canRenderAds(front);
@@ -136,7 +142,7 @@ export const FrontLayout = ({ front, NAV }: Props) => {
 		: [];
 
 	const desktopAdPositions = renderAds
-		? getDesktopAdPositions(filteredCollections, pageId)
+		? getDesktopAdPositions(filteredCollections, pageId, maxAds)
 		: [];
 
 	const showMostPopular =

dotcom-rendering/src/lib/commercial-constants.ts

@@ -1,9 +1,23 @@
+import type { ABTestAPI } from '../experiments/lib/ab-tests';
+
 /**
  * The maximum number of fronts-banner ads that can be inserted on any front.
  * fronts-banner ads are inserted from the desktop breakpoint.
  */
 export const MAX_FRONTS_BANNER_ADS = 8;
 
+export const getMaxFrontsBannerAds = (
+	abTests: ABTestAPI | undefined,
+): number => {
+	const isInVariantAdLimitGroup =
+		abTests?.isUserInTestGroup(
+			'commercial-fronts-ad-increase-ad-limit',
+			'variant',
+		) ?? false;
+
+	return isInVariantAdLimitGroup ? 16 : MAX_FRONTS_BANNER_ADS;
+};
+
 /**
  * The maximum number of ads that can be inserted on any mobile front.
  * Mobile ads on fronts are inserted up until the tablet breakpoint.

dotcom-rendering/src/lib/getFrontsAdPositions.ts

@@ -359,9 +359,8 @@ const canInsertDesktopAd = (
 const getDesktopAdPositions = (
 	collections: AdCandidate[],
 	pageId: string,
+	maxAdsAllowed = MAX_FRONTS_BANNER_ADS,
 ): number[] => {
-	const maxAdsAllowed = MAX_FRONTS_BANNER_ADS;
-
 	const adPositionsFromReducer = collections.reduce<{
 		heightSinceAd: number;
 		adPositions: number[];