Dear [Name],
We like to tell you how much we appreciate you on the daily. But the holiday season is the perfect occasion to show you our gratitude with a little extra something.
Please accept this [gift card / other gift] as our token of gratitude.
We're incredibly thankful for your contribution to our growth.
Our team and I send you the warmest wishes for the holiday season and we wish you and your family a happy and healthy holiday break!
Sincerely, [Company Name] Team