Amazon, which reports earnings on Thursday, does not break out its advertising sales, but nestles it in its "other" business segment.
"Google and Amazon require a user to already be looking for something, therefore aren't as reliant on cookies," Eduardo Cruz, performance marketing manager at SupplyKick.
"For brands selling a physical product, Amazon Ads are a powerful way to drive purchases, increase product consideration, and reach customers."
Apple's advertising business has surged since it prevented advertisers from tracking iPhone users without their consent in April, eating into market share once occupied by Facebook, Instagram and Snap.
The iPhone maker will report fourth-quarter results on Thursday.
Most Facebook users access the social networking platform through a mobile device, with nearly 15% of adults using iPhones and iPads in July, according to data firm Data Reportal.
Twitter, which relies on targeted ads but not as much as Facebook, reported advertising revenue in line with estimates.
Wall Street analysts said since the majority of advertising on Twitter comes from Brands, especially services or digital, as opposed to Direct ads, the company was better positioned to overcome the privacy changes than Facebook or Snap.
To be sure, the digital advertising market is still booming exponentially as the pandemic led to more consumers shopping online and spending more time on social media. Like Facebook and Snap, Google's YouTube saw a modest hit, the company said, primarily in direct-response advertising.
"This is the early innings of a shift that will play out over several quarters," Andrew Lipsman, eMarketer principal analyst at Insider Intelligence, said.
"The strength that we've seen in the past few quarters has remained, but it is starting to shift a little bit between the different players."
(Reporting by Nivedita Balu in Bengaluru, additional reporting by Aniruddha Ghosh, Writing by Subrat Patnaik; Editing by Lisa Shumaker) ((Nivedita.Balu@thomsonreuters.com; Twitter: @niveditabalu;))