Leftover Segments

Most of the time, when you create a segmentation model, the system automatically assigns one segment called Leftovers. The concept of leftovers is easy to grasp – basically it's the segment of customers that didn't fit into any of the other specified segments.

For example, say you are sending out an invitation for a big in-house sale. Suppose that you want to impress those customers who have purchased more than a specified amount in the last year by inviting them to a private pre-sale. Other than that, you don't care to break the customers down by any other criteria. You can construct a model like this:

Segment 1 – All customers who have purchased more than $500 in the last year
Segment 2 – Leftovers

Segment 2 then contains all customers who have purchased less than $500 in the last year. You may ask, "What if I want to specify all my segments and not have leftovers?" That's a great idea, but hardly practical in the real world. In any database, there may be unclassifiable data. Let's look at this simple model:

Segment 1 – All women
Segment 2 – All men

At the time of roll out, the system begins to assign customers in your audience to segments. What happens if a particular customer does not have the gender specified? Without the leftover segment, where is the system going to assign this customer? Without the leftover segment, this gender unspecified customer would not receive an e-mail.

It is important to note that the leftover segment functions exactly like any other segment in your model. You can send messages to leftover segments and view the results on reports.