Imagine your storefront being held in the hands of your clients, that is a catalog. They are excellent for both prospective and recurring buyers: prospective buyers will be delighted to see your products or services in detail, while recurring clients will use your catalog to check all that you offer.
Catalogs come in various sizes and formats, but they usually have a minimum of 8 pages. The maximum depends on the way you want your catalog to be.
They are generally expensive to print because of the amount of pages they have. However, they are such a good sale-oriented tool that the use of these catalogs ends up being a worthy investment.
Many companies made it possible to base their sales only on catalogs: they are efficient marketing elements.