1. Domain model provides a ubquitous language that ties domain experts and technologiests together.

2. Domain modeling and implementation should not be seperated and should belong together. Domain models aren't first modeled and then implemented, but evloved over time.

3. Domain design is closely related to the agile development process. Iterative development(XP,...); close relationship between developers and domain experts. DDD and agile reinforce each other.

4. The heart of software is its ability to solve domain related problems for its user. But some talented developers tend to pay more attention to the technologies used than the domain problem. They should deal with the complexity of the domain with high priority.