It’s known that Apple’s design teams “obsess over corners”—but that level of caring about detail need not be confined to electronics, or even excluded from disposable goods to earn a lasting bond with customers. I noticed this stickiness more than a year ago, but didn’t research its origins until this morning.

Say what you will about Starbucks vs. Peet’s coffee flavor (and do try Clover-brewed if you think the latter always wins out, but that’s another post); however there is more to the coffee experience than just that. Only a bit over 5% of Starbucks customers bring in their own cups or tumblers, which means >90% of customers use a paper or plastic cup. And those getting a hot beverage usually get one of those brown sleeves.

And how many times have you had a non-Starbucks coffee sleeve slip off the cup? How many of you noticed that Starbucks’ sleeves rarely slip off, and then peeled one off to discover why? Probably more than a few, but in googling for coverage of this, I only found one person who wrote about the glue’s impact on the customer experience.

Copywriter Jennifer Rotman blogged about her experience drinking from a coffee cup where the sleeve kept falling off. When she (like I) realized this didn’t happen with Starbucks coffee, she tore off the sleeve and found the little magical Unique Selling Point. In following the trail of the glue, I first found Starbucks’ 2005 patent for the generation of sleeve Jennifer noticed. This patent details some of the complex issues involved in manufacturing the sleeve—most notably the need to use a glue that would melt when placed against a hot cup of coffee, but which could be made to not melt during manufacturing when the sleeve is folded and the hot-melt glue that affixes the ends to form a ring is sealed in close proximity to the flaps. (Search for item “22” in the figures and description.)

That led to finding the press release and other references.

The person behind the Starbucks sleeve is Matthew Cook, of LBP Manufacturing, who is an inventor of many other food industry things, but the magic of the glue came from Henkel Corporation. You most likely do not know the Henkel name, but you know some of their brands: Dial soap, Locktite glue, and a few others.

The net win for Starbucks? This helped win me as a regular customer, but Jennifer said it best:

“If I can avoid hurtling along in traffic at the edge of disaster because of an errant coffee sleeve, I know where I’ll be buying coffee for the commute.”

And that’s the story small, usually unnoticed feature on a 3-cent sleeve won Starbucks a couple of loyal customers who shared their happy tales, gave Starbucks a bit of free PR, and probably won many more customers who noticed the benefit but didn’t bother figuring out why. All with about 1/10th of a cent worth of glue (from the maker of Dial) per cup of coffee.

Further Reading: