ZapBounce

ZapBounce and ConvertKit

ConvertKit, now trading as Kit, serves creators whose lists arrive from several places at once: a course platform, a previous newsletter tool, a lead magnet and a podcast sign-up form.

Each source has a different quality, and importing them together means the worst one drags the whole sending reputation down.

A creator's list is several lists pretending to be one

Subscribers from a lead-magnet download behave differently from subscribers who bought a course. The download list carries more throwaway addresses, because people wanted the file and not the newsletter.

ConvertKit bills by subscriber count, so every dead address from that old lead magnet has been on the invoice for however long it has been sitting there.

Their deliverability team watches bounce rates and will contact you about a list generating them. A creator sending one broadcast a week does not find out quickly, which means the damage accumulates before anyone notices.

How the data moves

  1. Export subscribers with their tags

    The tags tell you which source each subscriber came from, which is what makes a per-source verification report useful rather than a single number.

  2. Verify the whole export in one batch

    Duplicates across sources are collapsed before anything is checked, so someone on three lists is checked once and billed once.

  3. Import the verdict as a custom field

    ConvertKit custom fields work in segment conditions, so a broadcast can target confirmed addresses without deleting the rest.

  4. Verify new subscribers at the form

    ConvertKit forms can post to a webhook. Verifying there keeps the list from drifting back.

Setting it up

  1. Export all subscribers from ConvertKit as CSV, keeping the tag columns.
  2. Verify the file in one batch so duplicates across sources are collapsed.
  3. Compare the invalid rate per tag, which shows which acquisition source is producing bad addresses.
  4. Create a custom field for the verdict and import the results back.
  5. Unsubscribe the invalid addresses to remove them from the billable count.
  6. Fix the acquisition source with the worst rate, which is usually worth more than the clean itself.

ConvertKit: common questions

Which of my lists should I verify first?

The oldest lead-magnet list. That is where the throwaway addresses and the decay both concentrate.

Will this improve my open rate?

The denominator gets smaller, so the percentage rises. Whether more people read is a content question.

Does ConvertKit verify on import?

It checks format and removes hard bounces afterwards. Neither is a check before the send.

Reference

Check a ConvertKit export today

100 free checks a month, no card. Unknown results and duplicates are never billed.

Get an API keySee pricing