SUBSTACK WRITER CONVERSION

✍ 8,200 free. 3.4% paid.
Convert 40 this week.

Mainframe reads Substack data, flags the free readers who open every issue + share often, sends them the upgrade pitch in your voice. Paid bar grows without you pestering anyone.

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1,114,909 APIs· Pay-per-call· No keys. No configs. No signup.

The numbers that matter.

Pulled live from the tools you already use. One glance, every surface.

Free subs
8,200
+214 /wk
Paid subs
279
+12 /wk
Paid %
3.4%
+0.4pp
MRR
$2,680
+$180
Share rate
6.1%
+0.8pp

Workflows that run themselves.

Event happens. Mainframe picks the right adapter. It executes.

Paid-ready scoring

Score free subs on opens + clicks + shares, auto-send upgrade when 80+.

Thread to post

Turn a viral X thread into a free Substack + paywalled extension.

Comp expire

30-day free gift expires → send "extend or upgrade" 48h before cutoff.

Wired to the real APIs.

Bring your credential. Pay per call. Swap any one without breaking the others.

SubstackStripeBeehiivConvertKitKitResendNotionOpenAI

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