Erwin Greiner is a German businessperson who has been the head of 6 different companies and currently occupies the position of Co-Managing Director at diffferent GmbH, Managing Director at SYZYGY Performance Marketing GmbH, Co-Managing Director at Syzygy Media GmbH, Co-Managing Director at SYZYGY Performance GmbH, Chief Financial Officer of SYZYGY AG, Secretary & Director at Unique Digital Marketing Ltd. and Secretary & Director at Syzygy UK Ltd. Mr. Greiner is also on the board of Hi-ReS, Ars Thanea SKA and SYZYGY Digital Marketing, Inc (former Managing Director).

Erwin Greiner previously held the position of Managing Director at syzygy Deutschland GmbH, International Controller at Debis Systemhaus GmbH and Audit Manager at PricewaterhouseCoopers AG Wirtschaftsprüfungsgesellschaft.