Flickr: mediafury

Apple says there are 248,000 registered iOS developers in the US alone on its job creation page. This number leaves out:

• Developers registered in other countries.
• Mac Developers who may not have iOS dev accounts.
• Development team members who use a single account.

Assume that represents just a conservative 20% undercount, that would put the number of devs world wide (as in "Apple World Wide Developer Relations") at 300,000 more or less.

Number of seats available at WWDC: 5000.

You do the math.

WWDC ticket holders are roughly speaking the 1%.