Plumbing Inc. has been selling plumbing supplies for the last 20 years. The owner, Joe, decides that it is time to diversify by adding gardening tools to the products. Having had success using customer data to build predictive models to guide direct mail campaigns for special plumbing offers, he considers that data mining could help him to identify a subset of customers who should be good prospects for his new set of products. What would you suggest as the target variable? Is Joe ready to solve this as a supervised learning problem? Explain your reasoning.