Ferscha, A.Swoboda W.Wimberger, Ch.Fischer, StefanMaehle, ErikReischuk, Rüdiger2020-01-282020-01-282009978-3-88579-248-2https://dl.gi.de/handle/20.500.12116/31420Spontaneous interaction in public places has evolved as crucial concern in interaction design, particularly in the domain of public advertising. Implicit interaction is a mode of spontaneous interaction in which the user is not attentively or explicitly expressing input to a system, but the system from observing the user, and considering all the available information that describes the user situation, is used to generate input - and behaves accordingly. We have investigated implicit interaction as a potentially effective means to design for spontaneous interaction in the public. An en passant coupon collection system, CCS, has been developed to implement an implicit interac- tion based pervasive advertisement process. CCS is based on scanning and identifying Wi-Fi hotspots by their BSSID, and has been implemented for internet enabled smart phones. Scenarios demonstrate how the system collects bonus points, rewards, sales coupons, reward coins, etc. by users just walking by points of interest like stores, bus stops, schools or offices. CCS neither not being reliant to a preconfiguration of the Wi-Fi infrastructure, nor its use for wireless data communication, encourages for a parasitic use of existing Wi-Fi networks (already available in public places like shop- ping malls, airports, train stops, stations or city centers) as a pervasive advertisement system.enText/Conference Paper1617-5468