Substack doesn't function like traditional blogging platforms where you submit guest posts. Each newsletter is owned and operated by a single creator or team who controls all publishing. There's no submission portal or guest contributor system built into the platform. The workaround is collaborative content. Reach out to Substack writers whose audience aligns with your expertise and propose one of these angles: expert interviews where they feature your insights and link to your site, co-authored pieces if they're open to collaboration, or case studies where you provide proprietary data or research they can build a newsletter issue around. Most Substack creators are hungry for quality content angles, especially if you can offer exclusive insights their readers won't find elsewhere. Start by identifying newsletters in your vertical with 1,000+ subscribers. Smaller newsletters are more responsive, but you want enough audience to justify the effort. Read their last 5-10 issues to understand their style and what topics resonate. Your pitch should be specific—reference a recent issue and explain exactly what unique angle you'd contribute. Generic outreach gets ignored. Expect a 5-10% response rate on cold outreach, lower if you're pitching big names. The links you get are typically standard hyperlinks in the body text, which pass authority just fine despite Substack's domain structure. From an SEO perspective, Substack newsletters often rank well themselves and build engaged audiences, so the referral traffic can outweigh the direct link value. At Ottawa SEO, we've found Substack collaborations work best when you're genuinely adding research or data the creator couldn't produce themselves. Don't pitch recycled blog content. The platform's readers are typically more engaged than average blog audiences, so if you land a feature, you'll often see meaningful traffic and inquiries beyond just the backlink. Just remember you're pitching a person, not a platform—make it worth their time.