Data Warehouse measures without a corresponding dimension
The standard approach for handling missing dimensional data would be to enter a null value for the relevant data in the fact table. 

If this approach is problematic for some reason (table constraints, business rules) , adding a dimensional value to represent 'null' would be acceptable, if less technically correct. If you choose to implement this solution, keep in mind that you will need to consider that null &lt;> null for incremental processing.

Another possible solution would be to encourage the business (modify the application, change the data feed, consult with the outside data vendor etc.) to define a more robust salesCategory dimension- that is, define more cases for the dimension so that the number of missing values is reduced or eliminated and less holes in the data are present.