Its like any other medium for advertising and gaining publicity. A personal profile allows you to gain contact. A public profile allows you to increase brand recognition for a product. Depending on your needs and what you are marketing this might me a fast or slow process. Having a public profile as a bare minimum is always good for increasing social network links to your blog or website and help improve ranking. Good luck L
It can take a long time to build up substantial numbers of LIKE's on a public profile and therefore sales from your product through conversions.
you can upload that proudct on facebook and share to your friends as well as public also create page for each product of your site in facebook.