Thanks. What's not free are the hotels. Almost all increase their rates during this period, so book early.

CES is rather loose when it comes to whom could sign up to come (which is just about everybody). They say on their website:

International CES is not open to the general public. You must be in the consumer electronics industry to be eligible to attend the show.

But it's really only children they don't allow on the convention center floors. You do need to sign-up, and show ID to get your badge holder, for tracking and security purposes.

When you sign-up on the web, just about everyone is in the consumer electronics industry in some form. Just think about it. If you just have a flashlight at work that needs batteries, and tell your boss (or whoever supplies them) you need some D cells, then you're influencing their decision to buy batteries (a consumer electronic).

Even if you're retired, no one seems to care. Most vendors there are there to display and sell things. Everyone is welcome. Just bring ID. Also, bring something to carry stuff in. They say no luggage in the convention center, but small wheeled devices they seem OK with.