This post reminds me of Jim Collins' point in good to great:
"There are no homeruns to success. Just a collection of many, many hits"
One tool (i.e. Twitter) may not be the determining factor in finding a buyer, but it may be "the guide" that will get that buyer to a single property website, a virtual tour or a blog post where the decision will be made. There's definitely a process involved in selling in this new environment and providing maximum interrelated exposure is the way to go.