The Adoption Problem
Most business software is built to satisfy a buyer's checklist, not a user's workflow. This creates tools that are purchased but never truly adopted.
Design for the Daily User
The person signing the check and the person using the software daily are usually different people. Build for the daily user.
Simplicity Over Features
Every feature you add makes the product harder to learn. Be ruthless about what makes the cut. If it doesn't serve the core workflow, it shouldn't be in V1.