Action Center, October 2013
The Key Column name field in the "Create a destination..." dialog must contain the same parameter as the parameter designated as the primary key in the Email Service Provider (ESP) data table (in the Send field of the Data section of the dialog when creating an action).
Typically, this will be a user ID used to join to other user attributes available from the ESP. The dcsvid parameter is shown in the example below, but it is not always the primary key.
If the primary key parameter isn’t entered in the Key Column Name field, then the action will not execute properly.