I'm working on a project to try and predict which users would be most likely to subscribe to our services. I'm using R and am working with a data frame that has a user's email address, information about their past purchases (order count and revenue generated), how they have interacted with our website (different events triggered), and whether or not they have subscribed. I'm using this data to train and test different algorithms. I've used caret with knn, lda, cart, and nnet.
I've been able to get how accurate my models are but that doesn't help me know who to market to. When I plug new data into my model I would like to know which users it thinks are the most likely to subscribe and also give me their associated email addresses. I've looked all over but haven't been able to find anything that helps me pair a prediction to an email address. Any help would be much appreciated.
I'm not using the email addresses to classify the data. I simply have them to associate a row of data to a user. I had to get rid of them to run it through the training and testing algorithms and that is where I am having the issue of knowing what prediction data is associated with which email address and in turn which user.