Exclusive: Substack continues its acquisition streak with public correspondence startup Letter

Long-term gains seldom come without short-term pain as the state of Facebook’s ads business bares out. The social network has been at the sharp end of Apple’s crackdown on in-app tracking since it started three months ago. Media dollars have been paused and reallocated as marketers saw their ability to personalize ads impaired without an abundance of mobile identifiers to call on. Read more below.

• Facebook’s resilience shouldn’t take anything away from the turmoil many of its advertisers are currently experiencing.
• The acquisition comes as Substack’s biggest, newest competitors are trying to position newsletters as one hub in a larger relationship between creators and their audience.
• As developers look to integrate advertisements more seamlessly into their titles, ad tech companies are rising to meet the challenge.
• Sports publishers are building new franchises that will connect the newly available student athletes with advertisers. More in this week’s Digiday+ Media Briefing.
• Kajabi, a SaaS company founded in 2011, isn’t alone in reconsidering advertising on TV as DTC brands have added more TV to the mix.