diff --git a/app/multitenant/aws_collector.go b/app/multitenant/aws_collector.go
index d8e8c1721..2365f8c55 100644
--- a/app/multitenant/aws_collector.go
+++ b/app/multitenant/aws_collector.go
@@ -60,10 +60,11 @@ var (
 		Help:      "Total count of reports found in the in-process cache.",
 	})
 
-	reportSize = prometheus.NewCounter(prometheus.CounterOpts{
+	reportSizeHistogram = prometheus.NewHistogram(prometheus.HistogramOpts{
 		Namespace: "scope",
-		Name:      "report_size_bytes_total",
-		Help:      "Total compressed size of reports received in bytes.",
+		Name:      "report_size_bytes",
+		Help:      "Distribution of memcache report sizes",
+		Buckets:   prometheus.ExponentialBuckets(4096, 2.0, 10),
 	})
 
 	natsRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
@@ -79,7 +80,7 @@ func init() {
 	prometheus.MustRegister(dynamoValueSize)
 	prometheus.MustRegister(inProcessCacheRequests)
 	prometheus.MustRegister(inProcessCacheHits)
-	prometheus.MustRegister(reportSize)
+	prometheus.MustRegister(reportSizeHistogram)
 	prometheus.MustRegister(natsRequests)
 }
 
@@ -346,7 +347,7 @@ func (c *awsCollector) Add(ctx context.Context, rep report.Report) error {
 	// first, encode the report into a buffer and record its size
 	var buf bytes.Buffer
 	rep.WriteBinary(&buf)
-	reportSize.Add(float64(buf.Len()))
+	reportSizeHistogram.Observe(float64(buf.Len()))
 
 	// second, put the report on s3
 	now := time.Now()