Risto Rajala Matti Rossi Virpi Kristiina Tuunainen Janne Vihinen Revenue Logics of Mobile Entertainment Software - Observations from Companies Producing Mobile Games. 34-47 2007 2 JTAER 2 http://www.jtaer.com/aug2007/rajala_rossi_tuunainen_vihinen_p3.pdf db/journals/jtaer/jtaer2.html#RajalaRTV07