Avoiding the good/great chasm
You can be good at Twitter in about five minutes a day. Spending ten minutes doesn't make you twice as good... in fact, there's probably little measurable improvement. To be great at Twitter might take five hours of daily effort.
All the time in between five minutes and five hours is wasted. You're in a chasm with no measurable benefits.
We see the same thing happen with your Yellow Pages ads or your customer service. Showing up takes some effort and it often pays off. Showing up a bunch more is often worthless. If you want to truly be great, you're going to have to do things most people couldn't imagine. That's what makes it great, after all. The scarcity of it.
This is the underpinning of the Dip. Don't get caught doing more than you need to but less than you want to.