@inproceedings{ author={Alha Kati and Koskinen Elina and Paavilainen Janne and Hamari Juho and Kinnunen Jani}, year={2014}, publisher={DiGRA}, title={Free-to-Play Games: Professionals\&rsquo Perspectives}, isbn={ISSN 2342-9666}, booktitle={DiGRA Nordic \&\#3914: Proceedings of the 2014 International DiGRA Nordic Conference}, url={http://www.digra.org/wp-content/uploads/digital-library/nordicdigra2014_submission_8.pdf} }