What happens when the same content which is there on your website gets posted on your facebook and twitter accounts? Content duplication occurs and google has to decide which is the original content, and chances are that your website might be declared as not the owner of the content, and unfortunately this will effect your position in google!
To avoid that use canonical tag extension in magento! and don’t forget to add title/meta/description tags for all of your products
Get in touch with us at http://www.enlighteneditdevelopment.com To know more on how to make a website search engine friendy!