I am trying to predict - Number of days it takes for a customer to make the second purchase. Sometimes the customer comes back in 2,5,6,10.... days and sometimes the customer does not come back which is indicated by NULL in my data. Since my Target Variable can be NULL and some other values, should I think about using Linear Regression? Do you think Using Logistic Regression is better approach?
Also, if my target variable is right skewed should I apply transformations? Will it impact the way I analyze my results