The phrase "share traffic" can have multiple synonyms depending on the context it is used in. For instance, you could use the term "mutual exchange" to describe a situation where two entities share traffic, each benefiting from the other's position. Alternatively, "cross-promote" is a more specific way of describing the process by which two businesses collaborate to share traffic by promoting each other's products and services. Other phrases like "networking" or "collaboration" may be used to describe a broader concept of sharing traffic between multiple entities, rather than just two. In all cases, the goal is to increase exposure and reach by sharing traffic.