October 11, 2026

Newsletter platform Substack is increasingly being used by brands and creators for influencer marketing and sponsored editorial partnerships. Business Insider reported on brands using the platform to reach niche communities through storytelling, newsletters and creator relationships, alongside Substack’s expansion of sponsorship-related features.

Read the coverage: Business Insider: Substack’s influencer marketing era.

Why newsletters can work for brands

Email and subscription publications give creators a direct way to reach readers who have opted in. Compared with a fleeting social post, a newsletter can provide more space for explanation, product context and a consistent relationship with an audience. Results still depend on relevance, trust and the quality of the publication.

How marketers should evaluate a partnership

  • Check audience fit and recent engagement, not just subscriber totals.
  • Agree on the format, publishing date, disclosure language and approval process in writing.
  • Use tagged links or dedicated landing pages to measure qualified traffic and conversions.
  • Compare cost per engaged reader, lead or sale—not only open rates.
  • Protect editorial trust by avoiding scripts that make a creator’s recommendation sound inauthentic.

Where email marketing fits

For brands, creator newsletters can complement rather than replace their own email programme. A sponsorship can introduce a brand to a relevant audience; an opt-in landing page can then invite interested readers to receive the brand’s own updates with clear consent.

Privacy, consent and advertising-disclosure requirements vary by market. Make sure campaigns follow applicable rules and the platform’s current policies.