You need to have a Linotype FontExplorer X Store account to purchase fonts in the store. This account can be easily created with the Account Registration Assistant.
To open the Account Registration Assistant, open the Preferences, select Store and click on the "New account" button.
You need to be signed in in order to use the favorites, the shopping cart and the order history.
To sign in, click the "Sign in" link in the information area, which is located in the bottom-left corner of the Linotype FontExplorer X window.
You will be signed in automatically if your account information is entered in the preferences.