Business Insider: AT&T has lofty ambitions to change the way TV advertising is sold, but ad buyers worry it will become a walled garden like Facebook and Google

Excerpt: Other media buyers said that it’s too early to gauge how AT&T will use data across multiple properties but say the vision of an open marketplace remains appealing. TV advertising remains a massive business for advertisers and the ability to combine those linear spots with lucrative telecom data to fine-tune audience targeting and better understand how effective TV ads are is still a massive, untapped opportunity.

“The early days of Xandr haven’t been as clear in relation to how their data will be used across non-owned entities,” said Jason Smith, who leads digital investment for Mindshare Chicago. “We’re pretty optimistic about this idea of adding new inventory sources that scale up across premium video ad inventory with some level of data attached that are based off of a linear heritage.”

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