It’s clear that social media is delivering a wide range of interesting and beneficial online experiences for people. One that’s among the most highly valued is the ability to “vet” products, services and brands through reading reviews posted by “real people.”

According to a survey of ~3,330 consumers conducted in late 2011 by Deloitte’s Global Consumer Products Group, a large majority of consumers report that they rely on user reviews to guide their purchase decisions, rather than merely being influenced by brand advertising.

The Deloitte survey found that nearly two-thirds of consumers read consumer-written product reviews online. Of that group, 82% report that their purchase decisions have been directly influenced by these reviews – either confirming their decision to buy or causing them to switch to an alternative product or service.

Because of the perceived value of these consumer reviews, most people begin their search for information via a search engine query or by going to blogs, e-commerce sites such as Amazon that also feature consumer reviews, or review sites like TripAdvisor and Yelp.

By contrast, the incidence of people beginning their information quest at a company or brand website is far lower.

These dynamics are part of the reason why so many companies and brands are looking to increase their engagement with the online public. They’re particularly keen on ferreting out their natural allies – people who have a strong positive opinions about their brand – and turning them from armchair advocates into vocal cheerleaders.

For many marketers, this means going well-beyond collecting “likes” and similar “trophy counts.” They’re also continually monitoring comments in the social sphere concerning the quality of their products and customer service in order to make sure they deal with any issues or complaints expeditiously in order to minimize negative fallout in the “review” environment.

There’s also a powerful impulse for brands to offer “incentives” to customers in exchange for posting positive reviews. Those incentives can range from the small or innocuous – offering discount coupons or inexpensive product samples – all the way to incentives that seem more like bribes. (Here’s the latest example of this, courtesy of Honda.)

The keen attention companies are paying to social platforms reminds us that we’re in the midst of a migration away from traditional “push” marketing into a land of “pull” marketing.

There have always been “push” and “pull” aspects to marketing, advertising and PR, of course. But the balance of energy these days appears to be shifting quite sharply in the direction of “pull.”

There’s no reason to think that pattern will change anytime soon.