did you read the fine print?
Free Stateroom Location Upgrade: Upgrade applies to booking the stateroom location you wish to sail in for the price of the lowest category within that stateroom type during this promotion only. Offer is based on availability in like to like stateroom types (Interior to Interior, Oceanview to Oceanview, Balcony to Balcony, Mini-Suite to Mini-Suite). Upgrade offer excludes select categories, including but not limited to premium categories and suites. Offer does not apply to land portion of cruisetours. Offer is combinable with Princess Plus and Princess