The web was built on the idea of sharing and being social - it is hardly a revolutionary concept. What is revolutionary is the way marketers, consumers and businesses are using the web today.
Communicating and interacting via ever-newer, shinier, bigger, faster media tools and channels is what most of us mean when we talk about "social media."
And is this a bad thing? No way. Companies are coming to you, asking your opinion, begging for your attention - all so you'll give them just a moment of your time.
So leave that review, "like" that company on Facebook who offered the great Groupon deal and post a shout-out on Yelp to a company who gave you great customer service. The power is yours.