Tithing as a closing gift

I got to thinking about tithing and closing gifts at different points today. Thinking that I need to be more consistent with my donations even more so in this down economy. I was also thinking about some of the silly closing gifts I've purchased for clients that just bought a $700,000 property. I know that most people buying in that price range donate to one charity or another during the course of the year. Why not combine my tithe with a closing gift to my client? I've decided what I will do is take 10% of my commission check and split it with my client. 5% of that check will go to my church or charity of choice and 5% will go to that of my client. It seems like a win-win for both parties involved. I'll keep a running record here of the charities that we contribute to. I would love to hear someone else's thoughts on this subject.