Nati Shalom posted "Scaling Social Ecommerce: Architecture Case study," a blog post that covers some of the concepts around social graphs.
What is Social E-Commerce anyway?
According to wikipedia, Social Shopping is a mechanism for e-commerce where shoppers' friends become involved in the shopping experience. Social shopping attempts use technology to mimic the social interactions found in physical malls and stores.
A recent study showed that over 92 percent of executives from leading retailers are focusing their marketing efforts on Facebook and subsequent applications. Furthermore, over 71 percent of users have confirmed they are more likely to make a purchase after “liking” a brand they find online. (source)
It's a big architectural issue, and Nati's post starts to address why cloud computing is becoming such a big deal lately: localization of data and scaling out.
Scaling Social Ecommerce: Architecture Case study