Online communications consulting, specializing in environmental media


Figuring Out One Open Rate for Two MailChimp Campaigns

I recently took the advice of the good chimps at MailChimp and resent a campaign to folks who didn’t open it the first time.

Users of MailChimp may have noticed this feature. I think it was advertised to me, perhaps in an email from MailChimp (they’re good at sending those).

Resend My Friend

Essentially, resending an unopened campaign, as they call it, involves a few things:

  • You send your original campaign using the send time optimization feature (I find it works pretty magically)
  • You wring your hands, obsessively checking to see how your campaign is doing (open rates, clicks, shares, etc.)
  • After less than 24 hours has gone by, if you think the campaign didn’t perform as well as you’d like (benchmarks are nice to beat) you go to the next bullet point
  • You send out a second email of your original campaign to a group of people who didn’t open it the first time.

It’s pretty easy. All explained here by the MailChimp folks.

mailchimp bananas

Credit: J. Cornelius

It Works

So I did this and picked up 100+ new opens on a campaign I’d sent! Amazing! MailChimp warns that you shouldn’t resend if more than a day has elapsed since your original campaign. That’s what the data says. And you should expect some unsubscribes.

I didn’t receive any blowback. No unsubscribes. Just more opens! Why didn’t I do this a long time ago, I wondered?

Ah ha, it was because I was worried about how it would look in my archive, having sent the same campaign twice. It turns out that both the original and resent campaign will show up in your campaign archive when you do this little trick. This is a bit ugly but not the end of the world. And it’s fixable by arranging your campaigns in a folder.

I haven’t gotten that far yet, but I did arrive at the headline of this article.

Crunching the Numbers 

After the trick, I had two campaign reports, each with separate open rates. It seems easy enough to just add up total opens from the two campaigns and compare them with the original send list to come up with an overall open rate.

Not so fast. MailChimp doesn’t do such simple calculations. They factor click-throughs in with open rates to account for a margin of error created by using a tiny transparent image to figure out how many successfully delivered campaigns are opened by subscribers. Whew.

Just great. I’m a former journalist and I didn’t become a writer because I was good at math.

But here’s a workable solution:

Go to MailChimp/Campaigns, then View Report next to each campaign (one report for the original campaign, one report for the resent campaign).

mailchimp view report button


Success Means Reading Closely

If you simply divide total opens by recipients from the original campaign, you won’t find the right number. So I drank another cup of coffee, thought, and read closely.

Without knowing the secrets of how they factor in click-throughs, you can still create one open rate for two campaigns:

  1. Go back to MailChimp/Campaigns/View Report
  2. Write down the number of “Successful deliveries” (not recipients) for each campaign, original and resent. This number is right above “Total opens” on your campaign’s report page
  3. Right down the number of “Opened” emails from your original campaign (not the total opens). It’s the first number in the single-row, four-column table on each report page (duh)
  4. Repeat and add the original Opened number to the resent Opened number
  5. Divide the total number of Opened emails by the number of successful deliveries in the original campaign to come up with an overall percentage
  6. Rejoice.

With this method, the open rates for individual campaigns match the open rate in each MailChimp report, so I feel reasonably confident that 1-6 gives you a decent picture of how your campaign did (original + resent) overall.

MailChimp Doesn’t Explain This

Before I figured this out, I fired off a support request to MailChimp. It took me a bit to notice the “Opened” vs. total opens numbers and “Successful deliveries” vs. recipients. And it was early in the morning. In retrospect, I feel a bit stupid.

Unfortunately, MailChimp wrote back a day later without a solution. No help. They tried to sell me an upgrade to MailChimp Pro, which has a comparative reports feature. I’m already on the monthly paid plan. They alternatively suggested a third-party thing called EA Pro Reports, which doesn’t seem to include many instructions.

So for now I’ll stick with the paper, pen and calculator approach. Does anyone else out there have further insight? Have you tried the comparative reports feature, or EA Pro Reports?

— Jeff Kart