I remember when I tried to watch website visits, followers, email opens, and Pinterest saves… It was just too much. Yes, I tried to grow them all, looking at all of them. But it’s not the right way. The people at Morning Brew (yes, the daily email newsletter that delivers business and tech news has grown to over 4 million subscribers) did the right thing at that time. They picked one number to focus on. That’s how they grew. Trying to watch every metric only leaves you tired and confused. If...