The Marginal User is Your Toddler

At Facebook, Adriel Frederick would hunt for the marginal user - the person almost but not quite succeeding.

'When working on registration, I would try to find a country where we had a lot of growth, but for some reason our conversion rates were terrible. That's the marginal user. This is the person who is just on the cusp of coming in, wants to come in as you can see by the traffic, but we can't get them in. So why?'

In parenting, you have a marginal user too. It's whatever transition, routine, or behavior is currently almost working but keeps failing.

Morning routine working but bedtime is a disaster? Bedtime is your marginal user. Eating is fine but getting dressed causes meltdowns? Getting dressed is your marginal user.

The temptation is to keep optimizing what's already working. Resist it.

'When you go to the extreme and find that person who's the worst, you see everything that's wrong with the product.'

Fix the hardest part of your day. The rest is already fine.