Ask a computer what you can get by putting in a money amount in and it shall tell you a package of goods and services that when combined offer something useful to you in return for that money.. so if you put enough cash for a home renovation it shall show you ideas for a house renovation and be fully costed. If you have certain electronics it shall recommend what electronics to buy based on what you have such as accessories.
Imagine a database of products and services. Then you match packages of products and services of a particular theme together and sell someone a package of them together.
So if you also had a database of what you have you can predict what someone might want based on what they have. And what they don't have you can recommend something to buy.