A Bochur closed a Shiduch and during the meetings he was was guided by a friend whose guidance was very useful in sealing the shiduch. the Shadchan has already been payed in full. They have already been married and the Bochur wants to know if the friend should receive payment as well for his advice in the shiduch. The friend ultimately helped the Bochur form a very good impression on the girl.
While the Bochur may choose to offer his friend something as a token of appreciation, there is no halachic requirement to do so.
אפי’ את”ל שדינו כשדכן – ראה בתקנות פראג אות ד’ (נדפס בקובץ מוריה שנה ה גליון א-ג) ששדכן אמצעי יש לו שכר רק כשעסק עם שני הצדדים. וראה שו״ת בצה״ח ג, י. ועוד.