Tracking is done via Vercel Analytics, the analytics solution from Vercel, our hosting provider. The integration is done entirely via Next.js.
Vercel Analytics’ pricing system is based on events (page views + custom events). Our current plan includes 25,000 events per month for free, and then costs $14 per extra 100,000 events per month. Over 2023, we’ve averaged at roughly 55,000 events a month. So analytics should cost us $14 a month.
Custom events can be tracked via the helpers/track utility function. This only works on the client though, so make sure to only call it when the app has mounted (e.g. in useEffect React hooks). It is not possible to track server-side events with Vercel Analytics.