Publishers are bracing for a pullback in advertising amid the Covid-19 pandemic. And one big shoe has already dropped: Amazon and Walmart have temporarily suspended commerce marketing deals with digital media firms such as BuzzFeed, two people familiar with the situation said.

Commerce marketing has become an increasingly important part of revenue for online publishers such as Vox Media as well as BuzzFeed. Under most deals, the media sites publish posts about shopping with links to retail websites. If people click through the posts and end up buying something, the media sites get a cut of the revenue. BuzzFeed is more exposed than other digital media firms: It got about 20% of its revenue last year from the business, with half of that coming from Amazon and Walmart, the people say.