The sentence "Thank you for your continued support" is correct and usable in written English. You can use it in any situation in which you need to express gratitude to someone for their ongoing support. For example, you might use the sentence "Thank you for your continued support over the years - it has been invaluable."
Thank you for your continued support, and best regards for a fruitful new year as we continue this historic mission.
Thank you for your continued support of The New Yorker.
Thank you for your continued support of Harvard.
Thank you for your continued support, Jim Antol CEO and Chief Bottle-Washer Absterge, Inc.
Thank you for your continued support.
Thank you for your continued support and encouragement.
Thank you for your continued interest and support, and we look forward to seeing you soon!
We thank you for your continued patience and support as we work through this.
I want to take this moment to personally thank you for your continued encouragement and support over the past two years.
Thank you for your continued trust and support.
Thank you for your continued interest in and support for our mission.
Awesome tool! I started using it one year ago and I never had to look for another app
Ha Thuy Vy
MA of Applied Linguistic, Maquarie University, Australia