Keep blogs on main domain with easy subdirectory hosting

Many brands, publishers, and agencies—across an addressable base of roughly 3,000,000 SMBs—want blogs and long-form content to live on their main domain to protect SEO, conversions, and monetization, but find migrations expensive and technically risky when CMSes are hosted on separate domains. The pain points are operational and technical: redirects and canonical mistakes harm rankings, SSL and cookie scope complicate cross-domain setups, and agencies face one-off migration work instead of repeatable retainers. You could build a managed subdirectory hosting service that leverages programmable CDNs and edge/serverless reverse-proxying to mount third-party CMS content at customer.com/blog while preserving URL paths, status codes, and structured data, coupled with one-click migration tooling, canonicalization automation, analytics, and agency billing APIs. The market economics are attractive—about $4.5B TAM at an illustrative $1,500 ACV—and current trends (ownership-first publishing, edge adoption, and the agencyization of content) make the timing favorable; revenue potential is scored 78/100 and competition is medium, meaning execution matters more than timing alone. To differentiate, prioritize SEO-first engineering, strict security/isolation, measurable SLAs, and workflow features for agencies (white-labeling, monthly retainers, and billing integrations) rather than just raw hosting. Be honest about challenges: some third-party platforms will be incompatible with proxying, CDN egress and TLS complexities can raise costs, and building trust with enterprise customers will require audits and strong support. If you can solve those engineering and GTM hurdles, the combination of a large addressable market and clear agency demand makes this worth considering.