In order to reject all users, leave the Receives Original Stream column empty.
In Targeting, move Portland, OR. DMA to the Receives Alternate Content column.
In Targeting, select Country, and then move the United States and Canada to the Receives Alternate Content column.
In Targeting, select DMA, and then move all DMA’s to Receives Original Stream. In Exceptions, click Mobile.
In Targeting, select Source, and enter a source value.