I was listening to an ad on a college radio station in the middle of the summer semester. It was an ad for a local business. During the course of this 30-second ad, they managed to insult the Korean, Chinese, Japanese, Thai and all women everywhere. Now, needless to say that any type of racist or sexist attitude doesn't go far in advertising. Not only was this commercial poor advertising, but just plain stupid.
Gender bashing, racist remarks and general rudeness offends people.
You don't sell by offending others. The hardest of them to deal with is the use of gender in your copy. There are however a couple of other ways to help deal with this problem. One is two use plurals. Instead of his or her, try they, them or theirs.