* Type of trade show: A small, niche industry show will have far fewer attendees than a large, international event like CES or Hannover Messe.
* Location: Shows in major metropolitan areas or countries with strong economies tend to attract larger crowds.
* Year: Attendance fluctuates yearly due to economic conditions, industry trends, and global events.
Millions of people attend trade shows worldwide annually, but a precise figure is unavailable. To get an estimate for a *specific* trade show, you'd need to check that show's official website or related industry publications.