Segment (Twilio) is a customer data platform (CDP) — one API collects analytics events from your app and routes them to 400+ destinations (warehouses, ad platforms, marketing tools) without you wiring up each integration by hand. Its pricing is unusual: you're billed for Monthly Tracked Users, not events, and that has a sharp edge worth understanding before you wire it in.
| Plan | Price | Included |
|---|---|---|
| Free free tier | $0 | 1,000 MTU/mo, 2 sources |
| Team | from $120/mo | 10,000 MTU/mo, unlimited sources |
| Business | custom (~$25K–500K+/yr) | Unify + Engage + AI, identity resolution, SLA |
A Monthly Tracked User (MTU) is any unique user identifier Segment processes in a month across all sources — including anonymous visitors who've never signed up. If your marketing site sends page views into the same Segment source as your logged-in app, every anonymous browser session burns an MTU. A site with 50,000 monthly visitors and 2,000 real customers can blow through the 10,000-MTU Team plan on anonymous traffic alone, long before it reflects actual paying users. The fix: keep anonymous marketing-site tracking on a separate, cheaper analytics tool (or a separate Segment source you don't upgrade), and reserve your paid MTU budget for identified, logged-in users.
1. Sign up at segment.com and create a workspace.
2. Go to Connections → Sources → Add Source and pick your source type (Node.js, Website/Analytics.js, iOS, Android, HTTP API, etc.).
3. Segment shows a Write Key on the source's Overview / API Keys tab immediately after creation.
4. Drop the key into the SDK snippet Segment provides for that source, or send events directly to the Tracking API.
Track an event via the HTTP API:
RudderStack (open-source, self-hostable) offers a comparable warehouse-first CDP without the anonymous-MTU billing surprise if you self-host. PostHog (see our PostHog guide) bundles product analytics with a generous free tier and event-based pricing instead of per-user. Amplitude and Mixpanel compete on the analytics side but don't route to as many downstream destinations out of the box. Segment still wins on breadth of integrations if you need one event schema feeding dozens of tools.
Yes — 1,000 Monthly Tracked Users (MTUs) across 2 sources, enough to test the product but not to run production traffic on.
Any unique identifier Segment sees in a month, including anonymous visitors. This is the single biggest gotcha in Segment pricing — separate anonymous marketing traffic from identified-user tracking to avoid burning through your MTU budget.
Sign up, create a workspace, add a Source under Connections, and copy the Write Key shown on that source's Overview tab.
RudderStack's self-hosted open-source tier can be free beyond infrastructure cost, since it isn't metered by MTU. Segment's managed Team plan starts at $120/mo for 10,000 MTUs — simpler to run, but the MTU model can get expensive fast on high-traffic anonymous sites.
Not affiliated with Segment or Twilio. Prices are reference estimates — always verify on the official pricing page.