While walking past the landmark City Lights bookstore in San Francisco, I was delighted to find my Firecrackers book in their window display one Fourth of July in 2000. And on my first afternoon in London a year later, there it was again at the Dover Book Shop near Charing Cross Road. Experiences like that are always gratifying to an author.

But in this day of social media, I don’t think I was prepared for the immediate and immense feedback generated by the exhibition of my advertising icon collection. Besides seeing all the smiling faces enjoying the exhibition of A World Of Characters at the SFO International Terminal, here are some of my favorite tweets: