If you are a programmer, or someone in a small business, I highly recommend not only their products, but their book as well.
Here is a brief talk by David Heinemeier Hansson with a brief glimpse into how 37signals does it:
The secret to making money online
April 20th, 2008 | by matt | links
Apr
20
A programmer by trade, sysadmin by necessity, and iOS app enthusiast living in the Silicon Prairie.