Regarding Ed products sales

Hi, I am promoting Ed products like Viagra on my website. I would like to get sales for my products. Can any one suggest me the best ad network to get sales for my product. I need to get confirmed sales for my product other than impressions or clicks? Is there any ad network for that providing high conversion rates.

Can I do seo for my website to get sales? Is it possible? What are the techniques for it. Please help me