In today's information era, the ability to address the needs of potential customers at a moment when they are particularly receptive to the information provided becomes increasingly important. Modern mobile devices allow to collect precise data about the users' context, thus enhancing possibilities to better estimate, proof and react to current situations in real time. Given that, `context marketing' nowadays is an approach frequently discussed in literature. This contribution aims to systematize existing publications on the subject of context marketing, in order to build a basis for future research and to uncover potential gaps and contradictions in previous research. Methodologically, the two scientific databases “Scopus” and “Web of Science” were searched for context marketing related contributions. The evaluation made use of a mixed methods approach including a qualitative content analysis, and subsequently further quantitative evaluations. The findings reveal the majority of publications to focus on the user's location as the only context factor, resulting in a predominant focus on location-based advertising related research.

Standard telephone keypads are labeled with letters of the alphabet, enabling users to enter textual data for a variety of possible applications. However, the overloading of three letters on a single key creates a potential ambiguity as to which character was intended, which must be resolved for unambiguous text entry. Existing systems all use pairs of keypresses to spell out single key letters, but are extremely cumbersome and frustrating to use.Instead, we propose single-stroke text entry on telephone keypads, with the ambiguity resolved by exploiting information-theoretic constraints. We develop algorithms capable of correctly identifying up to 99% of the characters in typical English text, sufficient for such applications as telephones for the hearing impaired, E-mail without a terminal, and advanced voice-response systems.