There were even books that listed the companies, their addresses, and the free things they’d send you.

We went down a different path. We used to write to chocolate companies and they would send us free stickers etc. They advertised the product of course but it was fun.

We did Flat Stanley in second grade[1, circa ~2000], including mailing him to someone to send him on an adventure. I sent my Stanley off to Volkswagen and he came back bearing little toy pull-back VW Beetles and smelled like a new car…

[1] https://en.wikipedia.org/wiki/Flat_Stanley