While searching German comics publishers, I discovered a German comic con happening one week after the Frankfurt Book Fair: Comic Action 2012.
Here are the bullet points:
- Running since 1999
- Part of SPIEL, a massive games show (halls 4-12 in Essen, 8+9 for comics)
- 152,000 visitors, 763 exhibitors from 31 nations showing their products on 475,000 square feet of exhibition space (games and comics)
Games are big in Germany,with the Spiel des Jahres being a major international award. (Many get imported into the U.S.)
For comparison, GenCon usually attracts 37,000 attendees.