Substack is testing its first structured sponsorship program, allowing selected writers to insert paid brand placements directly into newsletters—an opt-in beta that keeps creators in full control and avoids programmatic ads. The move follows significant audience growth, with US uniques doubling in a year, but minimal marketer adoption: only 5% of brand marketers use Substack today. Sponsorships offer a way to monetize large free audiences while preserving the platform’s editorial identity. For advertisers, the beta introduces a premium, high-intent environment suited to thought leadership and niche expertise—an early indication that creator newsletters may become more formal components of influencer and upper-funnel strategy.

Reddit COO Jen Wong told EMARKETER that the platform has evolved from explaining itself to advertisers to proving it can deliver results. “We’ve shown Reddit can drive real business outcomes,” she said, noting that nine of fifteen verticals grew ad spend by at least 50% YoY. Wong emphasized discovery as Reddit’s next frontier—especially in underexposed sectors like parenting and sports—and said product improvements will make communities easier to find. With ad revenues projected to climb 46.6% in two years, Reddit’s opportunity is one of scale and visibility, driven by authenticity and high-intent engagement.

Travel media networks like Marriott, Expedia, and Uber are tapping loyalty data to compete in commerce media. To drive growth, TMNs are turning to off-site activations, cross-industry partnerships, and non-endemic advertising.

“Friday, Friday, Friday,” begins Amtrak’s recent viral social media video, in the retro style of monster truck ads. The content, which goes on to encourage train travel as summer begins (on Friday), has received over 500,000 shares across platforms, per Amtrak.