Conference attendance numbers....anybody got any data?

So I asked my Twitterverse this question and have been getting a few responses:

What's your best guess at conference attendance numbers?

I just came back from I/ITSEC and the estimate I got there was something around ~18,000 attendees. This number probably includes paying attendees, guests, and exhibitors but is still a darn healthy number. I've also heard that Game Developer's Conference draws about 18K but with fewer exhibitors (I can testify to that  - aside from E3 back in the day, I haven't seen an expo floor like IITSEC [but then I haven't been to CES]).

My own thinking is that conferences in the learning/training field osciallate somewhere between 1,500 and 3,000. Just wondering if folks have any other guesses as to the attendance levels at learning/training conferences, gaming conferences [to include the Virtual Worlds events] (thx Kurt for the reminder that GLS is capped at 400), tech conferences like Web 2.0, Enterprise 2.0, etc...

Thanks!

Updates:

One report is that Le Web has something like ~1700 folks

Comments

[Jay Cross]

Online Educa Berlin had 2064 registered delegates from 91 countries

* Sweden 76
* Finland 79
* Spain 88
* Poland 90
* Norway 149
* Netherlands 237
* UK 247
* German 291

Corporate Learning Trends & Innovation (entirely online) has 685 members in the community and more than that on the registration/mail list. Thanks to participation inequality, a good session had no more than 100 attendees. We'll see what happens as travel budgets evaporate and our continuing sessions kick off.