Most PLG teams that 'consolidate' on Mixpanel or PostHog discover later that those tools can’t reliably see ad clicks, can’t serve Conversion API events back to Meta or LinkedIn, and can’t bridge the marketing-site-to-app domain gap that loses most attribution. Each tool exists for a reason.
What each tool does best
Mixpanel and PostHog are exceptional at product analytics — feature usage, activation funnels, retention curves, cohort behavior inside the app. They’re weak at ad attribution because they’re typically only loaded inside the authenticated app, not on the marketing site where the original ad click landed.
Stripe is the source of truth for subscriptions, MRR, churn, and revenue. It doesn’t know which ad created the customer, and it doesn’t need to.
Cometly sits across the marketing site and app, captures the original ad click, ties it to the Stripe customer, and pushes deeper-funnel events back to ad platforms via Conversion API. It’s the connective tissue between the other two.
- Mixpanel/PostHog → product analytics, retention, activation
- Stripe → subscriptions, MRR, churn, LTV, payments
- Cometly → ad attribution, source ties, Conversion API, cohort ROAS
How they work together
A typical PLG ICP question — 'which channel produces customers that activate fastest and churn slowest?' — requires data from all three. Cometly tells you the channel, Mixpanel tells you activation speed, Stripe tells you churn. Each tool has its own dashboard for its own question.
Pipe Cometly’s source attribution into Mixpanel as a user property so you can run channel-segmented retention curves. Pipe Stripe events into Cometly so you have the revenue picture. The full setup takes one afternoon and gives you something that no single tool can do alone.
What to watch for.
- Trying to do attribution inside Mixpanel
Mixpanel can’t see ad platforms’ click IDs reliably and isn’t loaded on most marketing sites. Don’t use it for attribution.
- Skipping the source-property pipe to Mixpanel
Without the source property, you can’t run channel-segmented activation or retention curves. Wire it up.
- Treating Stripe as the attribution source of truth
Stripe knows the customer paid; it doesn’t know which ad created them. Pair it with Cometly for source attribution.
Recap.
- Mixpanel / PostHog → product engagement, activation, feature usage
- Stripe → subscriptions, MRR, churn, LTV
- Cometly → which ad / channel / campaign drove the user, then ties it to product + payment events
- Use Cometly to attribute, Stripe to monetize, and Mixpanel to retain
- Don’t try to do attribution inside Mixpanel — it can’t see ad clicks at the platform level