Merchandising offers an excellent way to improve your income because real football fans love nothing more than to bring home memorabilia from your team.
To produce the items like shirts and cups you need a factory. The more you expand your factory, the more items become available.
You also need a fan shop to sell your items, the bigger the shop, the more shelves and storage you have.
Note: Production of memorabilia won't start if your club balance is in negative state.
The higher you advance in your manager career, the more buildings become available!