What are the categories of promotional products?

Advertising Specialties
Ad specialties have these key elements: 1) an advertising or promotional message; 2) placed on (or with) a useful item, and 3) given with no strings attached.

Premiums and Incentives
Give a useful item with some strings attached (e.g. buy this book and get a free bookmark) and the item becomes a premium. A promotional product is a premium when it is offered as an incentive to produce a specific action.

Recognition Awards
Plaques, service pins, trophies, award jewellery and other gifts that signify performance or honours can be categorized as recognition awards.

Business Gifts
Typically given by businesses to customers and employees, and occasionally, to influentials and suppliers. In the context used here, business gifts are not extravagant gifts and trips. Gift-giving reasons cited by companies are: To thank customers, to develop business, to recognize employee performance and longevity, because customers expect them, and others.