The Business and Business Plus versions of Website Builder let you add favicons to your website (more info). However, the favicon only displays for visitors if they're using supported browsers:
|Browser||Oldest version supported|
|Internet Explorer||9 1|
|Safari||6 (using at least Snow Leopard/version 10.6)|
1 Internet Explorer versions 9 and 10 support
ICO files, but they do not get resized.