General Terms

With the advent of instant mobile messaging applications, tra-ditional SMS is in danger of loosing it’s reign as the king of mobile messaging. Applications like WhatsApp allow mo-bile users to send real-time text messages to individuals or groups of friends at no cost. While there is a vast body of re-search on traditional text messaging practices, little is under-stood about how and why people have adopted and appropri-ated instant mobile messaging applications. The goal of this work is to provide a deeper understanding of the motives and perceptions of a popular mobile messaging application called WhatsApp and to learn more about what this service offers above and beyond traditional SMS. To this end, we present insights from two studies — an interview study and a large-scale survey — highlighting that while WhatsApp offers ben-efits such as cost, sense of community and immediacy, SMS is still considered a more reliable, privacy preserving technol-ogy for mobile communication