Prime Day 2026 delivered another record event, with Adobe estimating U.S. online spending reached $26.4 billion, topping expectations and growing more than 9% year over year. Much of the post-event coverage focused on the broader “halo effect” across retail, with Walmart, Target and other competitors running overlapping promotions and benefiting from elevated online shopping activity. Several analyses also highlighted that Prime Day has evolved into a broader ecommerce event rather than one confined to Amazon alone.
However, Consumer Edge data reflects no meaningful evidence that Prime Day itself increased cross-shopping. That does not mean Walmart.com has not made meaningful inroads online – in fact, the data shows its share of online retail has increased from roughly 3% in 2020 to 7% today, underscoring its growing role in ecommerce. But when we look specifically at Amazon shoppers, their likelihood of also purchasing on Walmart.com has increased almost identically during Prime Day and during a typical week. The Prime Day premium has remained remarkably close to 1.0x every year, including 2026, suggesting Walmart.com’s growing overlap with Amazon shoppers reflects a broader year-round shift in ecommerce behavior rather than something unique to Prime Day.
We see a similar pattern for Target.com, where cross-shopping has also increased over time but shows little evidence of a meaningful Prime Day-specific boost.
Notes: Amazon cohort combines Amazon.com and Amazon Marketplace. Event window = Prime Day plus a two-day charge tail; baseline = average of three matched prior-week windows of the same length and weekdays. Card data captures completed purchases, not browsing.
