Internet users' behavior: a zero-memory consciousness game

Cory Doctorow gives in his blog a great example on what is the mode of thinking of internet users while surfing the web and how this has to be taken into consideration when trying to communicate or persuade them:

"[...] A friend who runs a small press recently wrote to me to ask if I thought he should release his next book as a Creative Commons free download in advance of the publication, in order to drum up some publicity before the book went on sale.

I explained that I thought this would be a really bad idea. Internet users have short attention spans. The moment of consummation — the moment when a reader discovers your book online, starts to read it, and thinks, huh, I should buy a copy of this book — is very brief. That's because "I should buy a copy of this book" is inevitably followed by, "Woah, a youtube of a man putting a lemon in his nose!" and the moment, as they say, is gone."

What are the implications of focusing on the now and on the external stimuli that invades our senses? Is the internet a medium that by definition can't make people reflect on a profound topic? Is the internet mainly a place where to look for instant gratification and stimuli?