Making your semantic application addictive: incentivizing users! - Cuel, Roberta; Tokarchuk, Oksana; Kaczmarek, Monika; Dzikowski, Jakub; Simperl, Elena; Lazaruk, Szymon (2nd International Conference on Web Intelligence, Mining and Semantics, WIMS 12, Craiova, Romania, June 6-8, 2012, 2012)