Bonus packaging with large blocks of colour can mislead consumers, according to research by Kai Purnhagen of the Law and Governance chair group and Erica van Herpen from Marketing and Consumer Behaviour.
In what is known as the Mars case, the court ruled that bonus packs of ice cream containing 10 percent extra but where the coloured bonus strip took up 30 percent of the packaging were not misleading. That conclusion was based on the assumption that the average consumer will read the packaging properly and is therefore fully informed, says Purnhagen. But he thinks that assumption is unscientific.
He and Van Herpen therefore set up an experiment with coffee packs. The participants, 126 Wageningen students, were shown different packs: one with the right bonus percentage in which the coloured bonus block took up a proportionate area, one with the right percentage and an excessively large coloured area, one with just the percentage and one with just the coloured area.
The results show that the size of the coloured area often has much more effect than the percentage figure displayed. If the coloured area is larger, people think there is more in the pack, even if it says 10 percent extra in both cases. They overestimate the amount by even more in packs without a percentage figure.
‘We haven’t checked yet whether this affects consumers’ purchasing behaviour,’ says Purnhagen. ‘For the law only sees it as misleading if someone then actually buys the product. That is something we have to investigate further in a follow-up study.’
For more information, read the blogpost of the researchers.