In a recent post, Dana Epp pointed to Eric Sink’s article about bugs and "code economics". I found it practical and interesting. Excerpt:

The six billion people of the world can be divided into two groups:

1. People who know why every good software company ships products with known bugs.
2. People who don’t.

Those of us in group 1 tend to forget what life was like before our youthful optimism was spoiled by reality.  Sometimes we encounter a person in group 2, perhaps a new hire on the team or even a customer.  They are shocked that any software company would ever ship a product before every last bug is fixed.