Yes! On-hold messages allow a company to market to the callers while keeping them on the line. A phone company can use on-hold messaging to tell customers about a new service or feature; when the caller reaches a live person, he/she has an immediate opportunity to ask about a feature mentioned in the message.
On-hold messaging also allows a business to connect a caller with information about and access to ordering a product or service immediately, increasing the chances the caller will buy it. Essentially, it's free marketing with very little additional cost to the business and instant listeners.