The definition of this offering, and how it relates to the customer and competitive offerings is a strategic position.
For a strategic position to be sustainable, the detailed activities required to deliver it must be different. The offereings and activities must force competitors to choose between maintaining their current strategic position - or attack yours.
If you're not familiar with strategic position, we encourage you to read Michael Porter's Harvard Business Review article "What Is Strategy?"
- Keep the description of the strategic position simple - just a few words.
- Your strategic position should not change much - should last for at least 10 years.