When the National Association of Realtors' national awareness campaign emphasizes that realtors know how to more efficiently market a client's property than an owner can by himself, it is highlighting which value of personal selling?

Saving time and simplify buying

Explanation:

Realtors in United States includes agents and property managers who works as commercial as well as residential real estates property brokers. They are members of National Association of Realtors in the United States and are highly specialized in buying and selling of properties in a highly efficient way. There are standardized process for selling and buying which makes the process easy and time saving.

Thus in the context, the awareness campaign shows the efficiency and simplifying way of buying and selling process.