I emailed Ralph Baer when I was about 13 to ask if he knew where I could get an original pong chip to build my own video game. He sent me an extremely nice response explaining that he didn’t have any of the chip any more, but that I didn’t need it to build my own version of pong.
I was shocked that the industry grew from $15 billion to $135 billion in a decade, but it looks like back in 2010 the actual size was about $80 billion. Not that I think he was being misleading or anything, I'm sure it was more of an offhand comment.
I really wish I could find that email.