When your online shop says #lessismore–An intervention study on the effectiveness of communicationto promote sufficient consumption

In order to meet the sustainability goals, a radical change in economy and society is needed (Tukker 2008). This requires changes in consumption levels and patterns as envisaged in the concept of strong sustainable consumption (Lorek and Fuchs 2013) or, in other words, sufficiency. Sufficiency aims at a reduction of material consumption levels in absolute terms while ensuring human well-being (Princen 2005; Gorge et al. 2015). Also, in the case of clothing consumption, a purchase reduction is necessary (Luz 2007) and among others,companies may be suitable actors to promote sufficient consumption (Bocken and Short 2016). Companies’ digital communication and especially commercial marketing is mostly thought to increase consumption levels and material aspirations by triggering gain and hedonic motives (Assadourian 2010; Varey 2010; McDonagh and Prothero 2014). Yet with sufficiency-promoting marketing, communication can also trigger normative motives to consume less or shifting hedonic and gain motives away from materialistic goals by showing co-benefits of a sufficiency-oriented lifestyle (Gossen et al. 2019). So far, the impact of sufficiency-promoting communication have hardly been investigated. In the current study, we examined whether sufficiency-promoting digital communication of an online-retailer changes the intention for sufficient consumption, as well as self-reported purchase behaviour, subjectively ideal level of consumption and the personal norm for sufficiency. Method. We conducted a longitudinal field experiment (one baseline and two post surveys) to test our hypotheses. The intervention included several communication measures of the online-retailer for sustainable clothing Avocadostore (newsletter, Instagram and Facebook postings) with the message #lessismore. Participants were customers of Avocadostore and were assigned to the experimental group (N=215) and control group (N=1895) by self-selection. Results. Comparing baseline and post measures, we found a reduced purchase of new clothes, increased care behaviour and a higher personal norm for sufficiency in the total sample. Yet, when comparing the experimental and control group, the groups did not differ in their behaviour change, thus the intervention itself was ineffective. Discussion. There might be a mere-measurement effect due to the survey (Morwitz and Fitzsimons 2004). Additionally, the sufficiency-promoting communication may not have been strong enough due to framing and the online setting. We would like to discuss these results, their implications and possible future research with the participants of the conference.