Simply replace the unfilled areas such as "[]" and "[date]" with your information.
Dear [name],
It is with great pleasure that we have recently welcomed [name] to our [business name].
[Name] was previously with [name of previous business] in [city] and we feel privileged that he has chosen to work with [business name].
We would like to take this opportunity to inform you of a new discount. [details of discount]
We felt you would want to hear about this and are hoping to see you in the near future.
Sincerely,
[name]