Dear Mr. Park
I believe that in my 7th year in service I have showed my worth as a marketing assistant in your respective company and I have developed my camaraderie towards my co-employee.
After being rated as outstanding in the my performance appraisal for 5 consecutive years and being awarded as one of the top sales earner for 5 consecutive years as well, I believed that I have grown enough from being marketing assistant in your company. It is always been a dream for me to become in the other level of my career and that is to be promoted as marketing head. This is a great opportunity for me aside from the monetary benefits, on the other hand, my purpose is to appraise myself and show more my great knowledge and apprehension.
Hoping for your consideration on my promotion. Thank you and have a nice day, it is a great honor to be part of your company.