Amazon wants to own the long game in ad measurement

“What we actually find is that roughly 20% of the sales value for a brand shows up over time and isn’t captured in that immediate attribution window because that’s just a cutoff date for measurement,” said Lily Tong, a director of measurement at Amazon Ads, “It doesn’t mean that you didn’t create value.”

She and her team have been trying to prove that out since October 2024, when Amazon unveiled a long-term sales metric in closed beta. It tracks shoppers new to a brand, meaning they haven’t bought from it in their past year, and their first key actions after seeing an ad, such as whether they searched for the brand or added one of its products to their cart. It then uses the brand’s historical 12-month return from shoppers who took the same actions to estimate what the campaign will generate over the next year.

Since the beta, Amazon has built on the idea of driving longer-term sales. Full-funnel campaigns, announced last November, tries to shift budgets across Sponsored Products, Sponsored Brands, display and streaming to drive long-term sales. This spring, Amazon also said it would extend the look back windows in its clean room. Soon, marketers will be able to check whether projected long-term sales came true and compare them with actual sales. 

These checks and balances matter since a branded search or filled cart is no guarantee of sale. Not all of those shoppers are going to end up buying something, but some will, said Tong. Shoppers who add a product to their cart and leave often come back and buy it within 12 months, she continued.

Brand advertisers, unsurprisingly, stand to gain the most from understanding those nuances, since their spend has been the hardest. They “can’t put a dollar value on” what those ads do, Tong said, so they fall back on brand lift surveys or proxy signals like search. That makes those brand ads hard to weigh against the rest of a media plan. “It’s very apples and oranges,” Tong continued. A dollar figure lets marketers set brand spend on Amazon against the rest of their performance advertising and therefore decide how much goes to one versus the other.

For their part, agencies are split on how well those efforts have worked so far. Some say long-term sales helps brands look past last-touch attribution and see how their ads move shoppers from discovery to purchase. Others treat it as a forecast that shifts whenever the campaign mix changes, and say the uplift Amazon credits to streaming TV doesn’t show up when they check it against actual product sales week by week.

The skeptics tend to do the measuring themselves. They build their own marketing mix models to tie Amazon spend to direct-to-consumer and in-store revenue. That takes data Amazon doesn’t always hand over easily. It gives agencies 90 days of historical sales data, while a marketing model needs closer to 18 months, though access has improved this year through a beta program. Amazon also prefers analysis to run in its clean room, where advertisers take out aggregated insights, which Tong put down to a “really high bar on customer privacy.” Ultimately everything rides on what the advertiser can get hold of. As Bryce Hamlin, vp of data intelligence at Power Digital, explained: “If the right data exists we see full visibility but that’s a huge ‘if’ depending on where the data is coming from.”

Until then, plenty of agencies will keep treating Amazon’s off-site numbers with caution.

“So far, we haven’t seen it move the needle,” said Radoslav Mazganov, vp and head of technology at Hyperzon by digital marketing agency Moburst in an emailed statement. “What we do see is off-Amazon spend showing up in the reports across our campaigns, with no sales behind it. For now, we’d rather keep this functionality limited to the minimum across our campaigns.”

That’s the gap Amazon wants to close. Omnichannel metrics, a tool built with industry partners, takes attributed Amazon ad exposures and looks at the sales they drive elsewhere. It covers consumer packaged goods and now automotive. Tong wants those figures in standard end-of-campaign reports so advertisers don’t have to opt into a separate third-party study. She pitched it at smaller advertisers in particular since marketing mix models tend to be “expensive and infrequent.”

Advertisers can still bring in almost any measurement firm they like. Tong continued: “We don’t point advertisers to our measurement. We basically say we’ll meet you wherever you want to go.” Some of those partners have turned up sales Amazon’s own reporting has missed. One study with an offline sales partner found Amazon’s streaming TV ads returned more than $2 in incremental sales off Amazon for every dollar spent.

Other work is at an earlier stage. Tong’s team is starting on benchmarks that show advertisers how they compare with direct peers or the best in their category.

The stakes are high for Amazon. Its ads already hold a place on media plans because shoppers buy there but proving they also drive sales across the open web and in stores is what would make the commerce giant the base the rest of the plan is built around, and justify moving more money into its DSP as search budgets shrink.