On the 9th of March, my website at mixxfeed.com was penalized in Google search results. The site receives around 20,000 visitors from Google on an average but that number has dipped to 350 after the penalty was imposed.
My site has been around since January 2010 and I confirm that I haven't done anything that may violate Google Webmaster Guidelines - there are no paid reviews, text ads, link exchanges, etc.
I do not employ any black hat SEO techniques or use the service of any SEO company to boost the search rankings of my website in Google.
I am really not sure what triggered the penalty but request you to remove it since I follow all Webmaster guidelines. Should you require any additional information, please do let me know.