An informed mutual decision with the customer on service/products is ___________.

An informed mutual decision with the customer on service/products is considered a successful sales transaction because it emphasizes the collaborative nature of the buying process. In such a transaction, both the customer and the sales associate share information and perspectives, leading to a better understanding of the customer's needs and preferences. This exchange facilitates an agreement that benefits both parties, where the customer feels confident about their choice and the associate successfully fulfills their role in promoting products or services. This kind of decision-making process fosters customer satisfaction and loyalty, which are crucial for repeat business and long-term relationships.

The other choices do not encapsulate the essence of a mutual decision in the sales context. While a necessary marketing strategy might involve multiple elements to communicate value, it does not specifically relate to the interactive decision-making process. A simple customer query implies a one-sided interaction where only questions are posed without an agreement on services. A promotional offer may entice a customer, but it does not necessarily involve mutual decision-making unless it is discussed and agreed upon collaboratively. Thus, the notion of a successful sales transaction accurately reflects the importance of mutual understanding and agreement in the selling process.