Basic ecard is a free card. Ads will be displayed on the same page as your ecard, the card will expire after 10 days and the actual card will appear smaller than the premium ecard.
When you send a Premium card, ads will not be displayed on the page together with your card, and the card will be displayed by 290% bigger than in the original view. Premium cards do not expire, and they can be printed out by both recipients and senders alike.