Substack Inc. vs Warner Bros. Discovery: Strategic Comparison

This in-depth comparison examines Substack Inc. and Warner Bros. Discovery across revenue, market value, business model, competitive positioning, and long-term growth strategy. Whether you are researching Substack Inc. on its own, evaluating Warner Bros. Discovery, or weighing the two companies side by side, the breakdown below highlights where each company leads and where the gap between Substack Inc. and Warner Bros. Discovery is widest.

On the headline numbers, annual revenue is $11.9M (FY2021) for Substack Inc. and $37.3B (FY2025) for Warner Bros. Discovery, while their respective market capitalizations stand at N/A and $77.0B. Both Substack Inc. and Warner Bros. Discovery are headquartered in United States. Their local markets and applicable rules may still differ.

Substack Inc.: Substack turned the email newsletter into a paid publishing business. Writers publish posts, podcasts and videos that go to subscribers' inboxes and the Substack app; readers pay creators directly, and Substack keeps 10%. By 2025 the platform hosted writers such as Heather Cox Richardson and The Free Press, more than 50 creators earning over $1 million a year, and over 5 million paid subscriptions. The company is headquartered in San Francisco, California.

Warner Bros. Discovery: Warner Bros. Discovery is headquartered in New York and trades on Nasdaq under WBD. It had about 35,500 employees at the end of 2025. Its brands include Warner Bros. Pictures, Warner Bros. Television, HBO, HBO Max, DC, CNN, TNT Sports, Eurosport, Discovery Channel, HGTV, Food Network, TLC, Cartoon Network and Warner Bros. Games. The company is headquartered in New York City, New York.

Substack Inc. and Warner Bros. Discovery pursue distinct approaches to generating revenue, and understanding how each company operates is the foundation of any fair comparison between Substack Inc. and Warner Bros. Discovery.

Substack Inc. business model: Substack is free to use for free publications. When a writer turns on paid subscriptions, Substack takes 10% of the revenue and Stripe charges its standard card fees. Substack does not run ads on publications. Revenue therefore scales with creator earnings, which is why the company invests in discovery features (recommendations, Notes, the app) that help writers sell more subscriptions.

Warner Bros. Discovery business model: WBD earns money from three revenue types. Distribution revenue comes from HBO Max and discovery+ subscriptions and from fees that pay-TV distributors pay to carry its cable networks. Advertising revenue comes from linear networks such as TNT, TBS, CNN, Discovery and HGTV, plus ad-supported streaming tiers. Content revenue comes from theatrical film releases, television production and licensing, games, and consumer products. Streaming and Studios are the growth segments, while Global Linear Networks still produces large cash flow but is shrinking with cord-cutting.

The durability of a company's moat often decides long-term winners. Here is how the competitive advantages of Substack Inc. stack up against those of Warner Bros. Discovery.

Substack Inc. competitive advantage: Substack's core advantage is distribution: its app, Notes feed and cross-publication recommendations help writers gain subscribers inside the network, which standalone email tools struggle to replicate. Writers also keep their mailing lists, which lowers the risk of joining.

Warner Bros. Discovery competitive advantage: WBD's main asset is its content library and franchise IP: Warner Bros. films and TV, HBO series, DC, Harry Potter, Looney Tunes, and a large unscripted catalog from Discovery, HGTV and Food Network. That library is the main reason it drew competing bids from Netflix and Paramount Skydance in 2025 and 2026.

Future prospects matter as much as current results. The growth strategies below explain how Substack Inc. and Warner Bros. Discovery each plan to expand from here.

Substack Inc. growth strategy: Substack's growth strategy centres on making its app a destination rather than just an email tool: Notes, recommendations, video and livestreaming give readers reasons to open the app and help writers find subscribers internally. It also recruits creators from other platforms, including a reported $20 million fund launched in 2025 to attract video creators.

Warner Bros. Discovery growth strategy: Before the sale, WBD's plan centered on growing HBO Max internationally, rebuilding the film slate and DC under DC Studios, licensing its library, and managing linear networks for cash. In 2025 it planned to split into two companies (Streaming & Studios and Global Networks) before the board ran a sale process that ended with the Paramount Skydance agreement.

A closer look at the financial trajectory of Substack Inc. and Warner Bros. Discovery rounds out the comparison.

Substack Inc.: Substack is private and publishes no audited financials. Its revenue comes mainly from a 10% fee on paid subscriptions sold by creators. Newcomer reported in 2025 that Substack told investors it had about $45 million in annual recurring revenue. Funding includes a $15.3M Series A led by Andreessen Horowitz (2019), a $65M Series B at a reported.1B valuation (2021), roughly $7.8M from a 2023 Wefunder community round, and a $100M Series C led by BOND and The Chernin Group at a $1.1B valuation (July 2025). That valuation implies a revenue multiple of roughly 24x on reported ARR.

Warner Bros. Discovery: FY2025 revenue was $37.3 billion, down 5% ex-FX, with net income available to WBD of $727 million, adjusted EBITDA of $8.7 billion, and free cash flow of $3.1 billion. The company ended 2025 with 131.6 million streaming subscribers and $29.0 billion of net debt. In 2026, Q1 revenue was $8.9 billion with a $2.9 billion net loss that included the $2.8 billion termination fee owed to Netflix, which Paramount Skydance paid on WBD's behalf. Q2 revenue was $8.7 billion, down 12% ex-FX, with net income of $149 million and adjusted EBITDA of $1.9 billion. During Q2 WBD repaid its $15 billion bridge loan with new term loans.