Dear Felix
I am writing to thank your for referring [NAME, ex. Mr. Johnson] to us. [STATE RESULT OF REFERRAL, ex. After demonstrating the Magna flux compressor, Mr. Johnson placed an order with us.] We will be pleased to serve [him/her] in the same capacity we have served you in the past.
As you know, [FIRM, ex. ABC Co.] values referrals greatly and offers [BONUS, ex. $1,000 for each reference which results in a Magna flux compressor sale]. We are hence pleased to forward to you [BONUS, ex. a check for $1,000] in appreciation of your referral.
You may always call me at XXX-XX-XX if I can be of any service to you.
Regards
Lydia