Plugging Spotify into Amazon’s demand-side platform will allow ad buyers “to reach engaged audiences at scale while providing access to full-funnel measurement and attribution,” the companies said. Now it’s bulking up on the audio front, adding Spotify after launching a programmatic ad pact with SiriusXM earlier this month. Audio is a “growing channel of consumption,” but it’s historically been underserved, said Meredith Goldman, director, Amazon DSP at Amazon Ads. In April, it launched the Spotify Ad Exchange (SAX) for programmatic ad buying with initial partners including The Trade Desk and Google’s DV360. In addition, Spotify is offering advertisers enhanced addressability for programmatic campaigns in Europe via ID5.