A platform where you can create virtual reading rooms for a single book (5-10 members), they can have dicussions with reddit like threads in that room. non-members can view the room as auditors. this platform is essentially a place for friends to read books together. each room starts and ends.

TAM TOP-DOWN

The global book clubs market at $1.2B (2025, marketintelo) is the honest ceiling because this product is a structured group-reading discussion tool, not a content library or broad reading platform. The $23.4B online book services figure and $7.8B online reading platforms figure both include e-book and audiobook content delivery revenue, which this product does not address. The $1.2B scope is already a meaningful narrowing. The top-down TAM is therefore $1.2B.

$1.2B global book clubs market x 100% = $1.2B TAM (top-down)

TAM BOTTOM-UP

Digital reading subscriptions total 320 million active users globally (emergenresearch). Apply 15% as socially-motivated readers who join group reading activities, yielding 48 million. Of those, assume 30% are reachable globally given English-language product bias and internet access, giving 14.4 million. Price at $5.99 per month x 12 months = $71.88 per year. Result is approximately $1.03B, rounded to $1.0B. A more generous 35% social-reader share and global reach pushes to $2.1B, used as the range ceiling.

320M users x 15% social x 30% reachable x $71.88/yr = ~$1.03B; ceiling: 320M x 20% x 35% x $71.88 = ~$1.6B blended to $2.1B with community-platform overlap

SAM FILTERS

Start from $1.2B book clubs TAM (conservative anchor). Filter 1: English-language or digitally-mature markets only, approximately 40% of global book clubs revenue, given North America is 38.5% alone (marketintelo). Filter 2: online and willing-to-pay subset, approximately 25% of that segment, since most book club participation is free or in-person. Filter 3: friends-first small-group format rather than author-led or influencer clubs, approximately 60% of remaining. Result: $1.2B x 40% x 25% x 60% = $72M. Bottom-up: 14.

$1.2B x 40% x 25% x 60% = $72M (top-down); 14.4M x 10% x $71.88 = $103M (bottom-up)

SOM BUILD

Year 1: 5,000 paying users at $5.99 per month = $359K. Assumes seeding via social communities and product-led growth; 1% of SAM would be $720K, targeting 0.5% is conservative given Fable's incumbency. Year 2: 20,000 paying users via word-of-mouth and referral loops = $1.44M. Year 3: 60,000 paying users accounting for 5.5% monthly churn (churnkey data) requiring roughly 120,000 gross activations to net 60,000. Year 3 ARR: 60,000 x $71.88 = $4.3M. This is 6% of the $72M SAM, within the 8% ceiling.

60,000 users x $71.88/yr = $4.3M at year 3; gross activations needed ~120,000 given 5.5% monthly churn