of these minor adjustments over time were the result of developing value proposition, ultimately leading to the success that Amazon.com is today. Lindic has developed a PERFA framework to evaluate this concept of value proposition in regards to innovation. Meticulously matching innovations' effects on customers with existing definitions found in the existing literature led to the following five elements that altogether represent a complete overview of all value propositions generated by innovations at Amazon.com. These are Performance (P), Ease of use (E), Reliability (R), Flexibility (F), and affectivity (A). Bonner states that the performances of innovations or new goods or services offered to customers is a result of a superior company's offering in terms of quality, technical performance, features and ability to meet customer needs and demands. This perspective emphasises innovation as a generator of performance in a customer-oriented way. Ease of use refers to the degree to which a person believes that using a particular system or product will be effort-free (e.g. the ease of search and acquisition, usability, personalisation, service, and support). All else being equal, a feature or application perceived as easier to use than another is more likely to be accepted by users, according to Wang. In Tornatzky and Klein's meta-analysis of the relationship between the characteristics of an innovation and its adoption, they found compatibility, relative advantage, and complexity have the most consistent significant relationships across a broad range of innovation types. Complexity is defined as “the degree to which an innovation is perceived as relatively difficult to understand and use”. Therefore, the easier it is to use an innovative application or feature, the more likely it is to be accepted by the user. Consequently, ease of use reduces the cost included in the value proposition equation and increases its value. Reliability is defined as “the ability to perform the promised service dependably and accurately” according to Pitt. Raaij and Pruyn similarly perceive reliability as the ability of a product to deliver according to its specifications. Innovation may, therefore, add to the value proposition for customers by performing in accordance with the standard set for products and services. Flexibility is perceived as necessary in order to maintain the fit of an organisation and a changing environment. It describes a firm's ability to reallocate and reconfigure its organisational resources, processes and strategies as a response to environmental changes. In other words, flexibility is materialised through the