Write It Down
Good PMs communicate direction in writing and verbally, in that order of importance. Written direction forces clarity, survives the meeting where it was said, and can't be misremembered. Bad PMs give direction verbally and informally, then act surprised when the product drifts.
The same rule applies upward. Good PMs take written positions on the hard calls: which features to build, which competitors to worry about, how to win. On paper, with their name on it. Bad PMs voice opinions in hallways, complain that the powers that be won't listen, and then say 'I told you so' when things go wrong. An 'I told you so' with no written record is worth nothing.
Horowitz extends this to work product generally: good PMs build collateral the whole company can reuse, FAQs, presentations, white papers. Scale through documents, not through being in every room.
“Bad product managers voice their opinion verbally and lament that the 'powers that be' will not let it happen. Once the product fails, bad PMs say 'I told you so.'”
Key idea
If it isn't written down, it isn't direction and it isn't a position. Writing is how a PM scales beyond their own calendar.