Economics of network industries (Shy)
Extraordinary Popular Delusions and the Madness of Crowds (Mackay)
The information Rules book belongs on your bookshelf if you want to understand how information goods are priced and how competition works in information driven industries. (Varian is now google's chief economist.)
The second one goes deep on the math of price-setting and standards wars.
And Mackay's work is a classic study of financial bubbles and panics.