Google I/O tickets are difficult to get - you apply, and they choose who can purchase a ticket by lottery.

One of the reasons for this is that they used to hand out swag worth more than the ticket price (latest Nexus phones, etc).

This makes sense for Google - increasing developer mindshare and experience on their platforms is worth more than the device cost. But this also had the effect of "everyone" applying for Google I/O to get the swag, even if you are not too excited about attending the talks.

I think you had to register. https://events.google.com/io2016/registration/apply/