The shapes a business takes.

Taking a percentage of transactions between two parties you never own the goods for, which produces beautiful margins and no inventory, and leaves the whole business resting on whether the two parties keep coming back through you rather than going round you.

A business that makes money by bringing two groups together who each need the other, where the decisive question is not what to charge but which side to charge, because the side you subsidise is the side that makes the whole thing work.

Most companies are three businesses wearing one badge: finding and keeping customers, inventing products, and running infrastructure at scale. Each wants a different cost base and a different pace, so holding all three under one roof means at least two are being run badly.

Sell the durable thing cheaply, sometimes below cost, and make the money on whatever the customer must keep buying afterwards, which works precisely as long as you can stop anyone else supplying the refill.

Giving something substantial away at no charge so that somebody else pays for it: an advertiser, a subset of users who upgrade, or the same user later, which works when the free thing costs almost nothing to reproduce and fails quietly when it does not.

Selling small quantities of a very large number of things, on the argument that when holding and shipping stock costs almost nothing, the combined demand for everything unpopular can exceed the demand for the few things that are popular.

Treating ideas as tradeable in both directions: buying in what you would otherwise have invented slowly, and selling out what you own and will never use, on the argument that most of what a business knows is sitting idle and most of what it needs already exists somewhere else.

Bespoke work turned into something with a name, a fixed scope, a fixed price and a delivery system that does not depend on which clever person is free that week, so the business can be sold, staffed and improved rather than merely performed.

Setting the price from what the result is worth to the buyer rather than from what it costs to produce, and in its strongest form tying part of the fee to whether the result arrives, which pays very well when it works and moves real risk onto you when it does not.

Charging a regular fee for continuing access rather than a one-off price for a transaction, which converts selling from an event into a relationship and converts profit from something you earn once into something you have to keep deserving.

Letting other people run your business with their own money, under your name and your rules, in exchange for a fee and a royalty, which turns a system you have proved into an asset that grows without you hiring anybody.

A business where the owner is the model: every relationship, judgement, price and recovery runs through one person, which usually produces good money, complete control and an asset worth a fraction of its earnings the day that person stops.