I would argue that marketers should use whatever they think will help them to sell their products, as long as they are not doing something that would break the law, like directly lying about what their product can do. I have three main reasons for thinking this.
First, it would be exceedingly difficult to write any law or any policy that banned the use of “sex” in selling goods or services. Imagine, for example, an advertisement with a beautiful woman (or a handsome man) who is fully clothed and holding up a tube of toothpaste. Does the fact that the person in the ad is desirable make this an example of using sex to sell? Now imagine an ad that shows men and women wearing bathing suits and playing in the water on a beach in Hawaii. Is this ad using sex to sell Hawaiian vacations or is it simply giving an honest depiction of what a tourist might do when on vacation in the islands? How are we to prohibit the use of sex in selling goods and services when it is so difficult to specify what constitutes using sex to sell?
Second, when we say that marketers should not use sex to sell, we are implying that sex (and/or the desire for sex) is a bad thing. Not all people share this attitude. For example, many people might think that the desire for status (the desire to make people think that you are important) is more shameful than the desire for sex. Others might feel that the desire to be rich is more shameful than the desire for sex. By singling out sex as an improper tool for use in ads, we stigmatize sex and label it as an undesirable and improper thing.
Finally, marketers would not use sex to sell if it were not effective. What this means is that consumers like such ads. If we ban such ads, we are essentially saying that we need to save people from themselves. We are saying that the people do not really know what is good for them and must be protected by the government.
Marketers should be able to use whatever means they want to sell their products. As long as they are not lying about the product, they should be able to make whatever ads will appeal to people. We should not try to make rules about advertising that A) are impossible to write, B) single out one human desire as improper, and C) go against what people manifestly want.