My daughter and I were given some promotional coffee mugs as we were walking out the door of someplace we just visited. My daughter took one look at her mug and said, "Um, Mom, this mug has been used!"
I'm not sure if it was simply dust or was dried up coffee. Either way, it didn't leave the best impression. It did, however, give my daughter and me a good chuckle. Should you be giving out any promotional items in the future, make sure you give them a good scrub first!