The present study builds on the concept of key success factors. Key success factors (KSF) enable a company to differentiate itself from its competitors and to offer a distinct value to customers or consumers [31
]. The unique selling proposition or USP [32
] chosen for communication is linked to a KSF. KSF stem from different sources, such as the macro-environment, the sector in question (such as the food industry), the competitive strategy, or the temporal factors of influence within the company [33
]. This implies a distinction between the external factors one cannot influence, but can only monitor and eventually act upon, and the internal factors that can be built on or developed further. It also implies that KSF can be looked at from different levels, such as the macro and micro level. Furthermore, success factors are interrelated as well as "embedded in a network of other relevant skills and resources" [33
]. Apart from research into KSF in areas such as mature markets and industrial products [34
], new product development [35
] and food markets [3
], detecting success factors is also important to evaluate communication and advertising effectiveness. The latter information is collected and reported by advertising award institutions such as the European Association of Communications Agencies (EACA) and the Institute of Practitioners in Advertising (IPA) in the United Kingdom [37
A case study approach was used to explore success factors in recent commercial marketing activities. Case studies, often used in social sciences, have the advantage of allowing the researcher to gather and generate knowledge and experiences about complex phenomena that are closely connected to a particular context [38
]. In business education they are valued because "by looking at many cases, one develops an understanding, an intuition for business ecology, which, in future problem-solving situations, will improve the ability to look at the right cues in the environment and come up with the right strategic decision" [33
]. Merriam [38
] recommends the case study methodology for "studying educational innovations, evaluating programs, and informing policy". It is thus an appropriate approach for identifying insights for future healthy eating policies and gathering insightful, practically relevant examples.
To ensure the quality of the research process with regard to validity, reliability and reflexivity, similar procedures are suggested for the conducting of case studies as for qualitative exploratory research in general [38
]. Therefore, a harmonised study protocol providing objectives and procedures was developed prior to the purposive sampling of cases. The research process consisted of several steps to allow for critical reflection. Multiple cases, sources and types of materials were used, multiple researchers were involved, and the process allowed for feedback from key informants.
The selection of suitable cases is crucial for a successful case study. The European commercial food market offers a vast number of food and beverage marketing campaigns, but only those that were actually successful in changing consumer behaviour are suitable for deducing valuable teachings. Therefore, this was the first criterion for campaign selection. However, general market data rarely allows individual campaign's effects to be singled out, and information about the success criteria for campaigns is largely proprietary data. To overcome these challenges, three methods of identifying suitable food and beverage marketing cases from the past 5 years were chosen (see Figure for an illustration of the selection process):
Selection process for marketing cases.
a) Cases were selected from those acknowledged by marketing effectiveness awards, on the grounds that the award reports contain actual market data as proof of campaign effectiveness, and that these cases have been assessed by an expert committee, which acts as a proxy for a peer-review process.
b) Twelve food market experts (see Table ), through interviews and email correspondence, identified examples of successful campaigns. This method was chosen because these individuals have knowledge of campaigns that are either too new to have been recognised by awards, or that were not eligible for the awards, because of being based on alternative marketing approaches rather than traditional advertising techniques.
List of the experts interviewed in the search for cases
c) Large food companies were contacted and asked to select and provide successful campaigns from their internal competition process. This method allowed the authors to access cases that were not eligible for awards due to company policy, and material that was not accessible elsewhere. It must be emphasised that the companies did not, however, have an influence on the authors's final choice of which cases to include.
Documents selected for use in the case study were mainly drawn from the award documents of the EACA Euro Effie awards, the national Polish Effie awards, the UK's IPA effectiveness awards, the Spanish Eficacia awards and the European IMC awards for Integrated Marketing Communications. Apart from the award documents, several expert reports were received from the consultant New Nutrition Business and internal documents on possible cases were provided by the companies or agencies contacted. Seven telephonic interviews were conducted with food market trend experts, and a further five experts gave valuable advice via email (see Table ). Keywords related to potentially interesting brands or campaigns were entered into Internet search engines to access additional publicly accessible documents and online media reports, and into YouTube for an indication of the popularity, content and format of TV advertisements.
Out of the 60 commercially successful cases identified, 27 were selected for further analysis using purposive sampling. Ten cases had won awards, 12 were recommended by the experts, and six were suggested by large food companies (three examples from Nestlé, two from Kraft foods and one from Unilever). Selection criteria included information being available from at least two different sources, and a distribution of cases across different regions of Europe, target groups such as age group, product categories, company size and type of marketing activities. Marketing activities encompassing different types of marketing cases, such as new product launches, product reformulations, new communication measures and cause marketing were selected, as well as examples of generic marketing and retailer activities for retail brands and assortments. Furthermore, selection focused on nutrition-related examples of food products and marketing in the broad sense, meaning that products either had to have favourable nutritional characteristics when compared with other foods of the same category (such as ice cream that had been reformulated to be healthier), or the campaign had to communicate health-related aspects as possibly perceived by consumers (such as the promotion of a passion for outdoor sports in relation to a chocolate bar). It is important to note that the investigators did not attempt to judge which foods are healthy, or whether a specific nutrition and health-related aspect in a campaign was actually promoting health. The aim was rather to identify successful marketing activities and communication approaches so as to extract potential success factors which, when transferred to public health promotion activities, could potentially improve their success and effectiveness.
During the data gathering stage, additional documents were collected and19 personal interviews were conducted - 16 with representatives of food companies and three with representatives of the advertising agencies for the selected products and campaigns. A semi-structured interview guide was used (see Table ) and the interviews were audio-recorded and transcribed verbatim for analysis.
Semi-structured interview guide
The data analysis process is depicted in Figure . The first step in analysing the data collected from the 27 cases was to assign a third of the cases to each project partner to conduct a case-by-case analysis and a comparative analysis of the subset. To control for reflexivity bias, at least two researchers read and reviewed the material in-depth and summarised the content of each case into a concise description based on a uniform template that factually described the case and noted observations or comments on the case. Possible success factors were preliminarily listed within the template. The second step was a joint comparative case analysis where each project partner prepared a presentation of their cases as well as a draft comparative analysis of their set of cases. These materials were shared during a 2-day workshop where authors and project partners with backgrounds in public health nutrition, consumer science, food marketing and advertising participated (see acknowledgments). The comparative analysis followed a stepwise procedure. Initially, individual cases, the preliminary list of success factors, and the three comparative analyses of the subsets were discussed by the group. Thereafter, additional potential success factors were brainstormed, using the information gathered in the first step as the point of departure. These success factors were written on paper cards and displayed on a board for better visualization. Next, the number of possible success factors was reduced using a card sorting method to identify the KSF: The discussion was facilitated by dividing the cards with similar meaning into piles. Each pile of success factors was elicited from several of the cases. Finally, the KSF were clustered into higher-order categories by combining piles that were closely related and deciding on a name that describes what they have in common. Clusters were formed because, although factors were different enough in type and application to be regarded as independent constructs, several appeared closely related enough to allow them to be grouped in a meaningful higher-order category. The clusters were arranged hierarchically and presented in a model that reflects the sequence in which they affect a marketing activity (see Figure ). The card sorting method is adapted from discussion facilitation techniques and is similar to the multiple sorting technique [44
Analysis process in the case study analysis.
Model of key success factors in commercial food marketing based on case study results.