If your site has links away to either affiliate pages or even affiliate accounting pages be very careful to apply rel=no follow tags. I have seen it affect many pages recently as they immediately move from number 2 to number 32.
Essential a link away from a page assumes that you are linking to this page because you are vouching for it’s content. If you are not voting for the amazing content on the page you are linking to, be sure to install the rel=no follow tag. This means that … yes, I am linking but I am not voting for this link.
The other issue is that you need to install the no follow so that your page rank doesn’t bleed off to these sites.
(The affiliate accounting pages I mentioned above are sites that help you calculate affiliate commissions. These generally go to the accounting site then redirect to the target site. This is the worst, as you are vouching for a redirect and Google will kill your site for it as you look like a thin affiliate site and remember they like thick non affiliate looking sites.)