There is a concept called "Social Networks as Contract Enforcement" in academic literature. Not only can you provide security in this instance but you can possibly do loans and other things which require trust. So for goods and services I think Steemit can expand into that too and compete with the likes of Open Bazaar with an edge.
- Social Networks as Contract Enforcement: https://stanford.edu/~arungc/CKL.pdf
Open Bazaar you say.. when the steem dollar marketplace launches, you wont be saying "Open Bazaar" anymore