Is open source health related to trade show attendance?

IDG has decided to offer free admission to Open Source World, the show formerly known as LinuxWorld, in a bid to spur attendance to the event this August in San Francisco.

This is not a problem endemic to open source. Trade shows generally have fallen on very hard times due to the recession.

Question is, does this reflect what is happening in the market, or just in the trade show business?

At CompuTex a few weeks ago organizers were overjoyed to report their attendance was level with a year ago. Most shows are showing big drops in attendees.

But does this mean the business is collapsing?

The last recession saw the development of open source as a market force, as users used sweat equity to get more value from their existing installations, in lieu of cash with which to buy improvements.

This recession catches that new industry starting to gain its footing. The trade show component is faltering. Is the whole indusry going down? What are you seeing?