The choice can largely come down to the commercial goals and the purpose of your website. Many businesses who sell products decide to place Adsense adverts within their website. This would appear to be a strange choice, opening up opportunities for rivals to promote their service or product to your potential customer base.
Many publishers claim that they are only doing this to allow companies who provide ancillary services to advertise. These claims have some merit, as those who for example sell pillows could provide those who sell bedding with an opportunity to advertise.
Although this would make sense, there are still those online retailers who allow rivals to penetrate their audience. Many claim that there are still benefits in allowing your direct competitors to advertise within your website. One of these is that ultimately if visitors wish to see your competitors they would be able to see them through a Google search regardless. This may be true however the thought of an established brand like coco-cola having a Pepsi advert in their website is not even a possibility.
Another factor which is considered in this situation is that publishers do not feel that Adsense is effective in making conversions. They feel that visitors who would click on adverts are not highly qualified customers, as they would quickly navigate to the materials or products that interest them if they were.
Despite Adsense being a questionable choice for online retailers, it is surely a good supplementary service for other varieties of online publishers. For example, a website which provides a free service like dictionary.com gets high levels of traffic, and is able to make their service profitable through adsense. This has been the case for Bloggers who originally provided content free of charge, being unable to reach the scale that is necessary to contract with advertisers directly.
This could also apply to other previously free services, including wider forms of information broadcast, and news for example. In 2006 a man who later published a selection of Videos claims to make $19,000 a month through adsense, claiming that he was also contacted through Google to help him increase the CTR (Click Through Rate) that he achieved. The thought of success like this has been a major factor in stimulating online publishers to opt for Adsense.
Many publishers also claim that adsense makes their website look more professional. Those who are able to contract with advertisers are generally seen to provide a service with large appeal, and therefore those unfamiliar with the program may feel that the Adsense advertiser is in this position.
Adsense however, is also aligned with those publishers who use the service purely to provide links to adverts. Everyone has done a Google search, clicked on an Adwords advert and came into a website which reads top ten resources on… This is a major problem, as is generally something that surfers find frustrating. If people see that it says adverts by Google, and they then see adverts by Google on another site, they may align that site with consumer unfriendly practices. This is therefore an issue which Google has to address, to maintain Adsense as a reputable service.
Regardless of the disadvantages and the websites for which the service may be inappropriate it is still a useful tool for website visitors. Those who visit a website, and click on a link provide revenues for the publisher, whilst those who provide free services are able to generate revenue.
The only fear that Google has, is that rival PPC programs offer better deals to publishers and they decide to go elsewhere, therefore taking advertisers with them. However, ultimately it is best for advertisers and publishers if they largely remain in same PPC circuit.