Most lock-in works by holding something of yours. Your files are in their format, your team is on their tool, your years of history live on their servers, and leaving means leaving all of it behind. The hostage is your data and the cost of switching is the ransom. Done well, you barely feel it: the defaults just make their thing the path of least resistance and everything else the path of more.
There is a cleaner kind, and a product can be built to produce it on purpose. You sell someone a plain, useful thing. You do it so well that, as a side effect you never charge for, the using of it changes them. The change is the lock-in, except the thing they are now bound to is not you. It is themselves.
Here is the shape, in the one I am building. The product I sell is help with your inbox: a tool that makes you faster and clearer at the daily work of taking signal in and sending your own back out. That is the whole pitch, and it is honest. But an inbox handled well is a mirror. To sort your mail the tool has to learn what you keep and what you wave past, which means it has to build a small, legible model of how you decide, which means it hands you, as a byproduct of clearing your queue, a picture of your own filter you have never seen straight on. I do not sell you that picture. It comes free, inside the price of the email help, because doing the email help well is impossible without producing it.
The free byproduct is where the want is born. Once you can see the shape of your own mind laid out, you start wanting to do something with it. Not file it. Act from it. You want the picture to start running your own commands back at the world, to become a thing you own and steer, a version of you that works while you sleep. You signed up for faster email and walked out wanting something else entirely. The product put the want there, by the ordinary act of doing its job.
Serving that want is a different product, and I have deliberately left it out of the first one. Turning a picture of your mind into a working version of it, wiring the specific commands that fit your specific shape, is delicate, person-by-person work. It is the kind of thing I do with you slowly, as a friend who has come to know you, not a feature you toggle. So it costs money, and it sits outside the email subscription on purpose. The first product solves being productive at email. It leaves building yourself a creature entirely alone. What it does, quietly, is wake the want in whoever was already carrying it. Many never feel it, and they clear the inbox, glance at the mirror, keep the email help, and owe me nothing more. But the person who was ever going to want to act on himself can now see what there is to act on, and he is the one who crosses the bridge.
The asymmetry is the part worth saying out loud. The first product knows the want is coming. He does not, not yet. He will cross that bridge soon, and he will enjoy it, and the crossing is paid for in part by the subscription he is already happy with, so the help he gets on the far side arrives feeling cheaper than it cost to make. He is being subsidized toward a desire he has not formed yet, for a thing only I am positioned to sell him. Stated that baldly, it is the anatomy of a trap.
One fact, and only one, turns the trap inside out. The thing you get locked into is yours. The model of you is readable by you, exportable by you, and the day you want to walk you take the whole of it and go, because that is how it was built. I keep nothing you did not choose to leave. So the lock-in is not the usual kind, where leaving costs you the hostage. There is no hostage. The only thing holding you is that, having once seen yourself clearly, you cannot go back to not wanting to. You are not locked to me. You are locked to you, and you can fire me tomorrow and stay locked exactly as tight.
Which is why graduation and lock-in turn out to be the same event seen from two sides. The free tool is built to graduate you: to teach you enough of your own shape that you stop needing it, hand back your data, and walk out the door. From the tool's side that is graduation, the customer leaving better off. From your side it is the moment the want ignites, the moment you become someone who will spend the rest of his life wanting to be more himself. The door you leave through and the hook you are caught on are the same door. You leave the product and keep the appetite, and the appetite is for no one but yourself.
The privacy boundaries are what make the hook a comfortable place to hang. Because the model lives on your side of the line and answers to you, the binding never reads as capture. It reads as waking up. Someone locked into a platform watches the exits; someone locked into himself just feels, more and more, like himself, and goes looking for more of it. The comfort is structural, the plain fact that there is no one in the room but you and the version of you that you are building.
I can write all of this down in the open, which is the last strange part. A real trap has to stay hidden, because the moment the mark reads the manual the spell breaks. This one survives being printed in full, for two reasons. Almost no one will follow it: the shape sits far enough off the standard map that it reads as a knowledge-garden curiosity rather than a business, and the incomprehension is the cover. And the few who do follow it find nothing to be angry about, because the worst thing I am doing to you is making you want to become yourself and charging you, fairly, for the help. The people who could object cannot see it. The people who can see it have nothing to object to. So I can just say it, here, where you are reading. The only lock worth building is the one that closes on the customer's own future, and it is the one you are allowed to describe to his face.