There are two ways to extend a business. Take inventory of what you're good at and extend out from your skills. Or determine what your customers need and work backward, even if it requires learning new skills. Kindle is an example of working backward.

Man is free at the moment he wishes to be.

An index is a great leveller.

If you're teaching today what you were teaching five years ago, either the field is dead or you are.

A few vices are sufficient to darken many virtues.