We're happy to tell you that Pack referral buttons are now available in additional languagues such as German, Portuguese, and Japanese. Don't forget -- when a Windows user you've referred to Pack downloads and installs it for the first time, you'll receive up to US$2 in your account.

To begin displaying Pack referral buttons on your site, simply choose Referrals from the AdSense Setup page of your account, then select Pack as the product to which you'd like to refer users on your pages.