Likelihood of confusion exists when a trademark or trade dress causes relevant consumers to be confused as to the source or affiliation of that product or service. Confusion can take place before the sale, at the point-of-sale, or after the sale.

The courts recognize two types of confusion in trademark or trade dress:

• Forward confusion occurs when consumers mistakenly believe that the junior user’s product or service is from the senior user or affiliated with the senior user’s products or services
• Reverse confusion occurs when consumers mistakenly believe that the senior user’s product or service is from the junior user. In other words, they mistakenly believe the junior user is the rightful owner of the mark. This occurs when a large, powerful junior user leverages its superior resources to quickly saturate the market of a small but established senior user with a similar mark on similar products or services. The danger with reverse confusion is not that consumers will believe that the junior user’s products originate with the senior user, but that consumers will mistakenly believe that the smaller senior user’s products were sponsored or approved by the stronger junior user. Because consumers have been bombarded by the junior user’s products and advertising, they may even view the senior user as having infringed the junior user’s mark. In either case, reverse confusion has the potential to harm the value of the senior user’s trademark, dilute its product identity and prevent it from controlling its reputation and goodwill with the public.

A likelihood of confusion survey assesses whether a “reasonably prudent” consumer would be confused by the use of similar marks on competing products. If a substantial number of respondents believe that the two marks are related or affiliated in some way, then there is strong evidence of potential confusion.