MediaRadar published an analysis on Monday of the top five retail advertisers, analyzing the amount spent this year from January 1-June 10 across digital, TV and print for Walmart, Amazon, Office Depot, Home Depot, and Target.

The top five companies collectively spent $1.03 billion year-to-date — up 8% when compared to a year ago, when they spent $954 million.

Walmart spent the most. In fact, the big-box retailer outspent Amazon by 6%, as the company prepared to promote Amazon Prime Day.

The amount Amazon spent on advertising fell 3% YoY in May, according to MediaRadar.

The data shows that Amazon invested more of its ad budget in print and digital compared to television from May 2020 to May 2021. The company moved a noticeable portion of its spending out of TV.

Amazon’s print and digital ad spend rose 129% and 27%, respectively. Television accounted for 73% of that total ad spend.

In 2019, MediaRadar reported in the month before Prime Day, which occurred in June that year, Amazon spent 28% more, compared with 2018. In the second quarter of that year, Amazon nearly doubled the ad spend behind Amazon Prime Video and its original content when compared to 2018. It also heavily promoted the shopping holiday on linear TV, with a 17% YoY increase compared with the first two weeks of July in 2018.

Unlike prior years, MediaRadar in 2021 found with for the exception of Office Depot, none of the companies increased the amount spent to prepare for Amazon Prime Day, which began today.

Office Depot’s ad spend was up more than 100% YoY in May 2020 versus May 2021. The data suggests this could be related to the company’s recovery from the pandemic period of more than a year, and not necessarily a response to Amazon Prime Day.

The data also shows that Target, Walmart, and The Home Depot had very small or negative YoY growth in the month of May 2021.

Television remains the format Amazon Prime Day has been promoted on most. So far in June 2021, TV has made up 60% of Amazon’s total ad spend, according to MediaRadar.

Amazon Prime Day’s creative is currently airing on more than 60 networks and has aired at least 2,200 times. Spend from this television campaign accounts for 15% of their monthly ad spend — June 2021.