Subscription and rebill
Plans, trials, upgrades and a dunning sequence that actually recovers failed charges. Most platforms lose more to silent rebill failure than to churn people chose.
Per-item payments
Tips, unlocks, bundles and time-limited access. Different flows, one ledger, so a per-item buyer and a subscriber are the same customer record.
Ad integration
Network tags placed so they do not cannibalise the paywall, plus an own-side impression counter to compare against what the network reports.
Affiliate and revshare
Postback tracking, revshare or PPS, cookie window rules, and a payout run that leaves an audit trail instead of a spreadsheet.
Reconciliation
Processor settlement files parsed and matched against internal records, with the differences surfaced rather than averaged away.
Reporting
Revenue by source, cohort retention and lifetime value, on numbers that match the settlement. A dashboard nobody trusts is worse than none.