I think this may be the exception, due to the topic. Usually if I see Adsense on a sales page, it tells me that the webmaster is not fully committed to making money from selling the product or service. That in itself raises doubts about its value.
Or that the webmaster is not looking to provide a service as much as making money from anything they can
Adsense is good for content pages not sites selling products. The ads may take your users to your competitors.
I think it depends entirely on the niche of your site, and where you place the ads. When you can, on a sales site, if your using ads place them well away from your sales description and payment gateway button, if you don't thats likely to cause potential buyers to click the ads and look elsewhere.