A friend of mine has started a Google AdWords campaign for his adult orientated website. Most of his keywords he thinks are adult, some of them performing very well, but some don’t trigger ads. In a comment he has found this: “adult classification is preventing your ad from showing …” He complains that the only adult words in his ads are ‘adult’ and ‘sex’. Still Google says “but the search query is not adult in nature”. My friend seems to be completely confused.The truth is that you are free to advertise adult contents on Google without difficulties provided that you have become familiar with a few restrictions and are ready to meet the requirements set by AdWords.With this article, however, I’d like to draw your attention to a common mistake which often causes frustration for adult content oriented account holders. The adult industry is regarded as a sensitive issue and if a specialist of AdWords finds that your keyword is not adult, it might be preventing your ad from displaying on the search result pages. E.g. an adult ad variation will not be triggered to show by a family-safe keyword such as “bookshelf”. Therefore adult site owners should only use keywords that clearly indicate interest in adult content. The point in the above is that your keywords are at the judgment of specialists, i.e. humans. I’ve heard rumors that one keyword was declined for an ad group while the very same keyword was approved for another ad group, evidently by another specialist. Whenever human judgement is involved you can never avoid such cases entirely.Therefore you are advised to use very univocal and unambiguous terms. E.g. many of us would think that the term “sex” relates to adult content because it may mean the genitalia or the instinct or attraction drawing one sex toward another etc. The specialist, however, may find that “sex” means either the male or female division of a species. In this case it is a purely scientific term and family-safe therefore he can rule to reject this keyword. The same refers, of course, to the term “rabbit”, “asses” etc. A “rabbit” might be any of several soft-furred, large-eared, rodentlike burrowing mammals allied with the hares while the term “ass” may refer to a long-eared, slow, patient, sure-footed domesticated mammal, Equus asinus, related to the horse, used chiefly as a beast of burden. To the utmost distress of many adult site advertisers such terms are in fact family-safe and not allowed to trigger adult ads. They should probably try to find 3-4 word unambiguous search queries.There has recently been gossip about Google replacing human judgement by mathematical algorithms for the purpose of deciding if a term is family-safe or not. However, this does not affect the contents of this article to a major extent.