Eat your own dog food

In software business, this means that you are using the software you developed like customers, so you can have the experiences as the users and can better understand their requirements and issues.

There is a good and a bad impact of this policy.

The key controversy is about which version of the software.  Following the thought, one may argue that the latest software should be always applied internally before shipping and sharing with customers.  The problems are

• The feature or the fix that the customer is looking may not be used at all due to the nature of the business.
• The internal IT may be regarded as an extended QA and keep getting the immature product from the development organization
• The issue of the product may interrupt the business
• The upgrade and patching cycle may be much more frequent than a normal business.
• The requirements and scenarios from the internal use may be unreasonably enlarged if they become the gateway for delivering to customers
• The release cycle may become longer with this additional step of "Internal IT validation"

 Overall, using your own product is definitely the right thing to do.  It still needs to be under control and the limit should be defined.  For example, only certain percentage of pass rate based on QA testing should be allowed.