title: Using BTYD to predict date and amount of customer's next purchase
body: <p>The BTYD package in R looks very useful for predicting future customer behavior based on past transactions.  </p>
  
  <p>However, the <a href="https://cran.r-project.org/web/packages/BTYD/vignettes/BTYD-walkthrough.pdf" rel="nofollow noreferrer">walk-through</a> only illustrates predicting how many transactions a customer will make in an upcoming period, for example in the next year or month. </p>
  
  <p>Is there a way to use this package to create a prediction for the date on which a customer will purchase, and the expected amount of the purchase?</p>
  
  <p>For example, using the sample data set available in the BTYD package:</p>
  
  <pre><code>cdnowElog &lt;- system.file("data/cdnowElog.csv", package = "BTYD")
  elog &lt;- dc.ReadLines(cdnowElog, cust.idx = 2,
                       date.idx = 3, sales.idx = 5)
  # Change to date format
  elog$date &lt;- as.Date(elog$date, "%Y%m%d");
  elog[1:3,]
  
  #   cust       date sales
  # 1    1 1997-01-01 29.33
  # 2    1 1997-01-18 29.73
  # 3    1 1997-08-02 14.96
  </code></pre>
  
  <p>I would want an output that has the customer number, expected next date of purchase, and expected purchase amount.</p>
  
  <pre><code># cust   exp_date   exp_sales
  # 1    1998-02-23   19.35
  # 2    1997-09-12   39.83
  # 3    1998-01-05   24.56
  </code></pre>
  
  <p>Or this package can only predict the expected number of transactions in a time period, not the date itself or the spend amount?  Is there a better approach for what I want to achieve?</p>
  
  <p>I apologize if this question seems very basic, but I couldn't find the answer to this conceptual question in the <a href="https://cran.r-project.org/web/packages/BTYD/BTYD.pdf" rel="nofollow noreferrer">documentation</a>.</p>