I got my nexus card just over a week ago

Here is what my account on the goes web site says about nexus cards and GI kiosks:

Global Entry Benefit: As a NEXUS member, you can now use the Global Entry kiosks located at the top 20 major U.S. international airports to enter the U.S. To use the Global Entry kiosks, you must use a valid machine readable passport. Do not use your NEXUS card in the kiosk, but you may wish to carry it with you. There is no additional cost to use Global Entry, and you may use it for the duration of your NEXUS membership. Additional information about Global Entry can be found at http://www.GlobalEntry.gov/. If you do not wish to use Global Entry kiosks, please disregard this message.

Someone a few posts earlier suggested that a nexus card can be used, instead of a passport. However, the statement displayed on account with the web site says otherwise.