This story was a blast. I loved it that the writer and main character didn't take themselves too seriously, but at the same time weren't silly. I also liked it that modern data visualization was a central part in a story set in an old used bookstore. More than one modern fantasy story has been set in a mysterious used bookstore, and these shops are often places of hallowed reverence for SFF fans, so I was braced for sobiety and cliches. Happily, neither were delivered.
I thought it was interesting how the author and main charancter went into such detail with the hypothetical situations that you couldn't really be sure whether he did them or not. Unfortunately, I meant to remember an example, but failed.
This story made me think of digital pictures and videos that I take. I take pictures of my kid, load them on to my computer, they are backed up offsite, some I send to my mom (where they are backed up again in my email account, her email account, her PC, her backup service), and some I post on facebook. I couldn't destroy those pictures if I wanted to even though they are made of impossibly tiny and ephemeral particles. While pictures taken of me as a child on the other hand, exist in hard paper, and are mounted in heavy books, but these books are among the family's precious treasures. You curse if you lose your computer in a fire, but you mourn the loss of a photo album.