Social Networking is another way to market and present YOU - then once people know you and follow your interesting content/feedback/communication you provide on your blogs you build up your personal brand - that is marketing. To convert your following to sales first requires methods of sorting your contacts, so you know who is a potential customer for your product and who is a potential advocate for your product.

At the same time you need to make it easy for people to connect with your products - making sure you have a link to your shop and a link to your newsletter / e-mail blog updates 'above the fold' on your website for example, so a person can always click on your store link or sign up to e-mail courses etc. easily, people can't be bothered to scroll down often on a website and sales of goods requires exposure to your products/services with permission over a period of time - if they can't readily see where to sign up or go to, they are less likely to go searching, or search a site with easier navigation.

For example there are compulsive buyers and people that need reminders/prompts - a trickle of info. over a period of time (and everyone else) So you need to look at your product/service offering and think how you can gear up your offers/present it to appeal to different types of buyer, then you need to test and tweak until you get conversions.

Big subject, but that is a couple things to look at.