The problem wasn't so much Penguin as it was Panda. Google has been going after affiliate sites for at least the last 5 years. The main problem is any type of data feed site, including those using the Amazon XML feed. The primary problem is the duplicate content. Thousands of sites use essentially the same content. I got around it for several years by using a home-grown content scrambler that spun the Amazon user comments and scrambled the sentence order. Amazon screwed us up when they put the user comments in an iframe.
My advice for any Amazon site is:
1) Write absolutely unique content. Never use Amazon's content and do not waste your time with content spinners or content from article marketing sites. They no longer work.
2) Use the nofollow attribute on all affiliate links. Matt Cutts recently recommended this, but I have done this ever since search engines started with the nofollow attribute.
3) Keep in mind that Google does not like anyone who makes money on the web unless their name is Google. They have very successfully trashed a wide range of internet industries, from directories to affiliate sites to article marketing sites to e-commerce sites adn now even sites with too many ads. One trick that appears to work is to make the site look like it does not offer products by writing very good informational content.
My problem is that I have too many sites and do not have enough time to research and write good content for all of them. I will probably trim down my list of sites and concentrate on 10 that focus on areas that I like to write about.
It was really nice when you could write an Amazon script that automatically added and updated 100,000 products, but those days are gone.
Habaku, some of your cherry juice articles do not use unique content. I suggest that you consider re-writing the articles and run them through Copyscape. Some are from ezinearticles.com, which is a kiss of death in a post-Panda environment.
The design for the cherry juice site looks very good.
"It's inexcusable for scientists to torture animals; let them make their experiments on journalists and politicians." -Henrik Ibsen