I've always wanted my own law. Here it is:
User experience time is logarithmic. The user's first 30 seconds on an application or web page is as important as the next 30 minutes. And that 30 minutes is as important as the next 3 hours.
Loren Burke, my usability mentor, created an entire business fixing the first 30 minutes of products that were about to be launched or which were already in trouble.
I am reminded of this as I am working on dashboards right now. Manage the first 30 seconds, then the first 30 minutes.
The next question then is whether to move on to the next 3 hours or to find another 30 second/30 minute problem to solve.