diff --git a/services/dataProcessor.ts b/services/dataProcessor.ts
index f315af1..575f108 100644
--- a/services/dataProcessor.ts
+++ b/services/dataProcessor.ts
@@ -448,15 +448,15 @@ export const processAdsCSV = (file: File): Promise<AdsRecord[]> => {
                         const countryRaw = getColumnValue(row, ['country', 'marketplace', 'portfolio', 'customer', 'kunde']);
                         const weekRaw = getColumnValue(row, ['week', 'woche', 'semana']);
                         const asin = getColumnValue(row, ['asin']);
-                        const costRaw = getColumnValue(row, ['cost', 'spend', 'ausgaben', 'gasto', 'coste', /ad\s*spend/i, /cost/i]);
+                        const costRaw = getColumnValue(row, ['cost', 'spend', 'ausgaben', 'gasto', 'coste', /ad\s*spend/i, /^cost$/i, /^spend$/i, /(?<!of\s)cost(?!\s*of)/i]);
                         const clicksRaw = getColumnValue(row, ['clicks', 'klicks', 'clics', /click/i]);
                         const impressionsRaw = getColumnValue(row, ['impressions', 'impresiones', 'imp', /impression/i]);
                         const cpcRaw = getColumnValue(row, ['cpc', 'cost-per-click', 'coste por clic', /cost.*per.*click/i, /cpc/i]);
                         const ctrRaw = getColumnValue(row, ['ctr', 'click-through rate', 'click-through-rate', 'click through rate', /click.*through.*rate/i, /ctr/i]);
                         const acosRaw = getColumnValue(row, ['acos', 'advertising cost of sales', 'aCOS', /cost.*of.*sales/i, /acos/i]);
                         const conversionsRaw = getColumnValue(row, ['conversions', 'konversionen', 'orders', 'pedidos', 'total orders', /order/i, /conversion/i]);
-                        const unitsRaw = getColumnValue(row, ['units', 'einheiten', 'unidades', 'units sold', 'total units', /unit/i, /einheit/i, /unidad/i]);
-                        const salesRaw = getColumnValue(row, ['sales', 'umsatz', 'ventas', 'ad sales', 'total sales', 'sales (30d)', /sale/i, /umsatz/i, /ventas/i]);
+                        const unitsRaw = getColumnValue(row, ['units', 'einheiten', 'unidades', 'units sold', 'total units', /\d+\s*day.*unit/i, /total\s+unit/i, /units?\s*sold/i, /^units?$/i, /einheit/i, /unidad/i]);
+                        const salesRaw = getColumnValue(row, ['sales', 'umsatz', 'ventas', 'ad sales', 'total sales', 'sales (30d)', /\d+\s*day.*sale/i, /total\s+sale/i, /attributed.*sale/i, /ad\s+sale/i, /^sales$/i, /umsatz/i, /ventas/i]);
 
                         if (!asin || !countryRaw || weekRaw === undefined || weekRaw === '') continue;
 
@@ -514,6 +514,11 @@ export const processAdsExcel = async (fileOrBuffer: File | ArrayBuffer): Promise
 
             console.log(`Processing sheet ${sheetName}: ${jsonData.length} rows`);
 
+            // Log column headers for first row to diagnose column matching
+            if (jsonData.length > 0) {
+                console.log(`[Ads Excel] Sheet "${sheetName}" columns: ${Object.keys(jsonData[0]).join(' | ')}`);
+            }
+
             // No need to skip index 0 since headers are mapped as keys automatically
             for (let i = 0; i < jsonData.length; i++) {
                 const row = jsonData[i];
@@ -522,15 +527,15 @@ export const processAdsExcel = async (fileOrBuffer: File | ArrayBuffer): Promise
                 const countryRaw = getColumnValue(row, ['country', 'marketplace', 'portfolio', 'customer', 'kunde']);
                 const weekRaw = getColumnValue(row, ['week', 'woche', 'semana']);
                 const asin = getColumnValue(row, ['asin']);
-                const costRaw = getColumnValue(row, ['cost', 'spend', 'ausgaben', 'gasto', 'coste', /ad\s*spend/i, /cost/i]);
+                const costRaw = getColumnValue(row, ['cost', 'spend', 'ausgaben', 'gasto', 'coste', /ad\s*spend/i, /^cost$/i, /^spend$/i, /(?<!of\s)cost(?!\s*of)/i]);
                 const clicksRaw = getColumnValue(row, ['clicks', 'klicks', 'clics', /click/i]);
                 const impressionsRaw = getColumnValue(row, ['impressions', 'impresiones', 'imp', /impression/i]);
                 const cpcRaw = getColumnValue(row, ['cpc', 'cost-per-click', 'coste por clic', /cost.*per.*click/i, /cpc/i]);
                 const ctrRaw = getColumnValue(row, ['ctr', 'click-through rate', 'click-through-rate', 'click through rate', /click.*through.*rate/i, /ctr/i]);
                 const acosRaw = getColumnValue(row, ['acos', 'advertising cost of sales', 'aCOS', /cost.*of.*sales/i, /acos/i]);
                 const conversionsRaw = getColumnValue(row, ['conversions', 'konversionen', 'orders', 'pedidos', 'total orders', /order/i, /conversion/i]);
-                const unitsRaw = getColumnValue(row, ['units', 'einheiten', 'unidades', 'units sold', 'total units', /unit/i, /einheit/i, /unidad/i]);
-                const salesRaw = getColumnValue(row, ['sales', 'umsatz', 'ventas', 'ad sales', 'total sales', 'sales (30d)', /sale/i, /umsatz/i, /ventas/i]);
+                const unitsRaw = getColumnValue(row, ['units', 'einheiten', 'unidades', 'units sold', 'total units', /\d+\s*day.*unit/i, /total\s+unit/i, /units?\s*sold/i, /^units?$/i, /einheit/i, /unidad/i]);
+                const salesRaw = getColumnValue(row, ['sales', 'umsatz', 'ventas', 'ad sales', 'total sales', 'sales (30d)', /\d+\s*day.*sale/i, /total\s+sale/i, /attributed.*sale/i, /ad\s+sale/i, /^sales$/i, /umsatz/i, /ventas/i]);
 
                 // Skip if missing essential data
                 if (!asin || !countryRaw || weekRaw === undefined || weekRaw === '') continue;
@@ -538,6 +543,11 @@ export const processAdsExcel = async (fileOrBuffer: File | ArrayBuffer): Promise
                 const weekNum = parseInt(String(weekRaw));
                 if (isNaN(weekNum) || weekNum < 1 || weekNum > 53) continue;
 
+                // Log first parsed row per sheet for column match diagnosis
+                if (allData.length === 0 || (allData.length > 0 && allData[allData.length - 1]?.year !== year)) {
+                    console.log(`[Ads Excel] First row sheet ${year}: costRaw="${costRaw}" salesRaw="${salesRaw}" unitsRaw="${unitsRaw}" acosRaw="${acosRaw}"`);
+                }
+
                 allData.push({
                     country: mapCountryToMarketplace(String(countryRaw)),
                     year,
diff --git a/services/experimentAnalysis.ts b/services/experimentAnalysis.ts
index 4c1d673..86a53a9 100644
--- a/services/experimentAnalysis.ts
+++ b/services/experimentAnalysis.ts
@@ -110,7 +110,7 @@ function getMetricValue(w: ComputedWeeklyMetrics, metric: string): number {
     case 'ctr': return w.ctr;
     case 'roas': return w.roas;
     case 'revenue': return w.revenue;
-    case 'acos': return w.cost > 0 ? (w.adRevenue > 0 ? (w.cost / w.adRevenue) * 100 : 100) : 0;
+    case 'acos': return w.cost > 0 && w.adRevenue > 0 ? (w.cost / w.adRevenue) * 100 : 0;
     default: return w.units;
   }
 }
@@ -173,8 +173,7 @@ function avgMetric(data: ComputedWeeklyMetrics[], metric: string, durationWeeks:
   if (metric === 'acos') {
     const totalAdRevenue = data.reduce((s, w) => s + w.adRevenue, 0);
     const totalCost = data.reduce((s, w) => s + w.cost, 0);
-    if (totalCost === 0) return 0; // No ad spend → ACOS is 0
-    return totalAdRevenue > 0 ? (totalCost / totalAdRevenue) * 100 : 100; // Cost but no ad revenue → 100% ACOS
+    return totalAdRevenue > 0 && totalCost > 0 ? (totalCost / totalAdRevenue) * 100 : 0;
   }
 
   // For absolute quantities (units, revenue, sessions), we sum them and divide by the duration