Distributed Computing Economics written by Jim Gray in 2003 is a good start. See this quote:
From this we conclude that one dollar equates to
- = 1 $
- ≈ 1 GB sent over the WAN
- ≈ 10 Tops (tera cpu operations)
- ≈ 8 hours of cpu time
- ≈ 1 GB disk space
- ≈ 10 M database accesses
- ≈ 10 TB of disk bandwidth
- ≈ 10 TB of LAN bandwidth
Obviously the values have changed since then, but this is very concrete data pointing to the fact that performance counts.
A more recent post related to this subject on High Scalability blog: At Scale Even Little Wins Pay Off Big – Google And Facebook Examples.
solved What is the value of performance in an application, in dollar form? [closed]