I started out thinking the same way until I did a little research first. Probably came at it the same way as you, but once I hit the point of “assuming” that bottle shrinkage was for packaging cost reasons and that “certainly” the makers aren’t supplying more liquid, it dawned on me that those were two dangerous absolutes upon which to jump to a conclusion. Surely it is not beyond believability that consumer impact might play a role — in which case, why exclude the marketers from contention as the source of the over-fillage?

One good authoritative reference on the subject, the classic insomnia-curative “The Handbook of Beverage Packaging” (1999, Geoff Giles, Editor), acknowledges consumer sensitivity on this topic:

“No consumer likes to a bottle that appears to be only partly filled”

and identifies the quick, one-time emotional response available at the point of purchase and first use:

“the successful package supports the brand through differentiation at the point of sale, [is opened] … and is then discarded by the consumer, without giving the package a second thought”

and again later, commenting on what beverage packagers apparently refer to as “snap-back” (releasing the semi-vacuum), that, to consumers:

“The shape of the bottle shoulder can either exaggerate or minimize the effect of volume change”

clearly indicating that even the most bland of intra-industry publications acknowledge a strong consumer-effect component on beverage container shape and fillage.

Taken at at face value, and in an area in which the company has already put valuable resources into specialized manufacturing of the container shape, it would almost be incompetent of the company’s marketers to ignore a known emotional-response opportunity to positively persuade at a key moment.

Marketers often make mistakes but they rarely make systemic mistakes. Perhaps the fact that everyone is now doing it is evidence that the Slurp-Factor(tm) works? Anyway, it’s worth considering and thanks for being a regular reader.

We underestimate our inner Slurper at our peril!

Sheesh.

I love their Rx Energy Herbal Tonic like you wouldn’t believe.

There aren’t many companies that give you more than you expect these days.

That’s sad.

I think you are right, the extra slump is made up many times over in customer loyalty and more purchases of the product in the long term. I often get emails telling me how great our customer service is, in many different ways. It just has to help the business in the long run to treat the customer as fairly as you can and sometimes, even going way beyond what the customer expects. I just replaced an Audio Bible product after the customer had ordered it 11 months ago.

We already give a 60 day money back guarantee which is twice as long as most, which I think lets the customer know we are there for the long run. I basically gave them another Audio Bible for free, this my not show up in the short term but in the long term treating people well, pays off.

Learn from the best minds in marketing every week by enjoying the best of the Web. This week includes Mike Moran, Escape from Cubicle Nation and Grok Dot Com.
……

Surprise and delight. I’m not sure why more people don’t care about this simple idea, but it really can bond a person to a product or a company. It just takes a little thought, and hopefully some Marketers can step away from the media buying long enough to use their empathy on the product side.

Here’s a couple more examples of surprise and delight, one for customer acquisition, the other for customer retention:

Acquisition:

http://blog.jimnovo.com/2008/01/13/geo-demos-work/

Retention:

http://blog.jimnovo.com/2007/03/12/new-customer-kits/