Hi, I am wanting to start an online business where I will be writing my own articles (mainly about general health, nutrition and exercise) and will also be wanting to have affiliate links with third party vendors. My question is, the bodybuilding industry has tens of thousands of products and thouands of companies, do I have to have a written agreement with each one of these companies although I myself was not going to recommend or sell them myself directly? Instead, it will be similar to how nextag.com operates (all links to other websites where shoppers can buy). If I were to have a product description, can I take it directly from the manufacturer's website? Or do I need written permission to do so?