On costco.com, advertising and tracking add ≈ 6,889 g CO₂ per million pageviews (4,559 g from ad-serving alone) — 1.3× the index average, cleaner than 24% of the sites we measure.
Ad-relevant
6889
g CO₂ / 1M pageviews
Ad-serving only
4559
g CO₂ / 1M pageviews
83
kg CO₂ / year at 1M pageviews per month
24
% cleaner than the DACH index
34
% of the footprint is tracking overhead, not ad-serving
Measured on the live electricity grid from public page-load data — an estimate of a site's ad-tech architecture, not a measured campaign figure. See the methodology →