To use the "auto fill names" feature for your eCard greeting, you must have an address book entry with a first name for each contact you are including in the eCard send list. When your eCard recipients pick up their card, their first name will appear in the greeting. If you do not have a first name for the recipient, your alternate text will appear. If you did not select alternate text, then nothing will appear in the greeting line of the eCard.
For more information, view the composing your eCard tutorial.