Their IPO made me look up what TAM was, and TBH it looks like the kind of metric where you're allowed to draw the boundaries however you like.

To the extent that they're not actually wrong about that TAM:

https://en.wikipedia.org/wiki/Total_addressable_market#/medi...

Note that I am not claiming they'll get sales anywhere near to close to the TAM. It's not like Wikipedia's market value is even close to {peak price of Encyclopedia Britannica} * {number of people on the internet} even despite it no longer being generally contested which of Wikipedia and Britannica is now better.