DAX calculating prior year sales on "lost sales"

[cr731]

I have a data model with a Sales fact file and Date table and am trying to calculate, for each customer by month, what are the last year sales where the customer has been lost? Lost is defined as where there has been no sale for 3 months past the last order date.

So my formula is

=
CALCULATE (
    CALCULATE ( SUM ( Sales[Net Revenue] ), SAMEPERIODLASTYEAR ( 'Date'[Period] ) ),
    FILTER (
        Sales,
        MIN ( 'Date'[Period] )
            > CALCULATE ( EDATE ( MAX ( Sales[Period] ), 3 ), ALL ( 'Date' ) )
    )
)

But this just gives me blank for everything. Not sure what the issue is?

 

[Matt Allington]

This is a complex topic and your formula is not going to work. I suggest you read the lost customer formula here New and Returning Customers – DAX Patterns

 

[cr731]

Thanks; I have read and reviewed that page... however I could not figure out how to modify the formulas to return prior year sales on lost sales. My Sales table is also simpler than what is in that model because my dates are only by-month - i.e. 1/1/2015, 2/1/2015, not specific dates throughout the month.