We went to dinner today at a chain restaurant because we had a gift certificate for it. Knowing that servers often get stiffed by people using gift certificates, I was prepared to tip 20%.
When time came to pay, our certificate was worth $50, but our bill was only $41. I handed the server the certificate, assuming that he would return with either $9 or $9 worth of store credit, depending on the rules of this particular chain.
However, he just returned with a "thanks" and our receipt, beating a quick retreat before I realized that he had returned neither store cred or cash. We were left confused- had he kept the $9 difference for himself as a tip? That would have been fine, because that's almost exactly what I was going to tip in cash, but I've never heard of gift certificates being able to be used for tips. I was wondering whether to still leave a tip, or if he had absconded that $9 difference for himself.
Since we never saw the $9 again, I assumed he had kept it for himself so we left no cash on the table. Did I do the right thing? Did I stiff him? Is this common practice for servers?
Thanks for any insight.