Hello!
One option for companies is to look to electronic Christmas cards. For various clients we have developed e-mails designed with their brand and including holiday styles and messaging.
For one client that is a group of orthopedic surgeons, we do a photo shoot each year with a different theme, then create a very creative flash site around those shoots with animation and music. An e-mail will be sent to a large list of contacts and then a custom card is designed and sent via the mail to specific people.
It is not only nice, but they have become well known in their area for the campaign and many people look forward to it each year. The holidays are a great time of year to do marketing that is relationship building.