Propensity model with Only Positive Data Is it possible to build a propensity model (i.e., the likelihood that a user will buy an item) using only positive values.
For example, I have a bunch of data about Customers (people that bought stuff) and Users (people that haven't bought stuff yet)
I want to get the likelihood that a User becomes a Customer.
It seems that the only way to do so is to train a model using the data of Customers, therefore using only Positive values.
The model built using only positive value will be biased towards positive value and will always predict for the customers who bought any items before. But customers who didn't buy anything,  the model won't be able to predict anything.