Pay per click advertising is one of the biggest online advertising methods, and adult advertising is one of the main industries on the Internet. However the attitudes of pay per click companies vary widely when it comes to allowing adult adverts. Many main-stream ad networks have taken different approaches to the issues surrounding adult pay per click advertising making it difficult for both advertisers and publishers in the sector.

Many people think that Google does not allow adult advertising, but this is not the case. There are many items prohibited by Google's advertising policy including gambling, tobacco and the sale of endangered species, but adult advertising is acceptable. Google accepts adult pay per click adverts however the policy prohibits certain of the more extreme genres.

Yahoo! Search Marketing also allows adult advertising but places restrictions on the sites making sure that they all have age disclaimers in place. All pages are rated as either adult or non adult and adverts for adult sites must be placed on keywords that are obviously adult in nature. Of course ensuring that keywords are entirely adult may prove difficult for advertisers in the adult industry for example the keyword sex may not be perceived as an adult keyword because it can be used in a non adult way such as denoting gender.

Unlike Google and Yahoo, Microsoft have chosen to shut-out the adult industry. Microsoft AdCentre do not accept adverts on keywords that they perceive as adult nor do they allow adverts that use landing pages that feature content of an adult nature.

Another of the big players in the pay per click industry Miva, has taken a slightly different approach by allowing adult advertising but requiring that the advertisers confirm that the advert is adult in nature when it is placed. This ensures that adult adverts are not shown in inappropriate locations.

Of course there are a number of specialist companies that concentrate on adult pay per click advertising. Using a specialist firm can be a better solution for many advertisers as there are no issues involved with the adverts showing on sites that may disapprove of them.