At first glance, I’d say that you’re right that it might be of concern that some web-based e-mail clients don’t show images by default. I haven’t checked with MailChimp specifically to see if Gmail triggers an “open” even if images are not loaded by default.

That said, the purpose of all of my testing was to reduce spam complaints, and I can share that since I started testing — and since I’ve written this article — the 1 and 2-star customer lists have always gotten a high occurrence of spam complaints, while the 3-5-star “best customer” list gets next to none. In that regard, this method is successful.

The key here is paring the 1 and 2-star contacts, then segmenting contacts into 2 lists on subsequent sends (1 and 2-star customers and “best customers”). I don’t pare after every send, only about once every six months.

I’m also measuring engagement in clicks, not opens, so though the “best customer” list open rate remains very high, clicks are much higher than the other list as well.

Don’t get me wrong, the idea is sound, just don’t take the ‘open’ stats as gospel..

An Alternative approch would therefore rather be sending your inactive users a mail to ask them if they would still like to receive your mails. if so they should click on a posted link. if they dont do this after you tried it 3 times every few weeks, throw them out of you list, they seem to be really dead or uninterested emaildresses.

There was actually an increase in sales that resulted from the e-mail campaigns over time. This could be due to seasonality, though none of the tests were not conducted after early November. Proof that if they don’t open or click, they don’t buy. Remember, we’re pruning the recipients that never open or click e-mails…

But how much did you lose in sales? One sale could beat that.

You’re certainly correct that it can be difficult to persuade clients to try this. Here’s what I would recommend. Get your client’s approval to send the message to the entire list, but segment the list into 1) one- and two-star rated recipients and 2) three-star and above recipients. Send them the same message, then show your clients the stats/results afterward. It may take a few mailings to convince them to prune, but you may eventually may get approval. At the very least, you’ll interest the client in campaign results and engage them in the process.

I hope this works for you! Feel free to come back and share your results.