Twenty years ago, our friend Dan did meticulous research on lawnmowers, comparing price and quality, reading Consumer Reports, and talking to various salesmen, asking questions at local stores. Once he decided which brand and model to buy, we piggybacked on his research and bought the same one because we knew he did a thorough evaluation.

While influence is nothing new, the many ways we’re influenced is, in more and more ways.  If you consider all of the consumer buying decisions we make: where we shop and dine out, which movies we see and what music we listen to, we have always made decisions with influence from our family, our friends, and, even perfect strangers.

Now, in addition to in-person influence, we are often influenced by a virtual community made up of people that we know, and their friends, many who post their opinions on , by liking a page, or on Amazon, by reviewing a product, or on Yelp, by reviewing a restaurant or local business.  (Yelp, by the way, got in trouble with site users for manipulating reviews in favor of advertisers and has changed their policy based on widespread negative feedback.)

That’s why has been making it easy for companies to incorporate the Like widget on their websites and blogs. Everything you “like” is cataloged for all of your Facebook friends to see.

This summer, my family decided to take a road trip, and I started using Foursquare, which posts my visits to restaurants and hotels, as well as my review of the experience.  Location-based social influence is in its early stages with the general public, but growing.

Recently, Google has started incorporating reviews into search results. Rather than navigating to a review site, google delivers the reviews,  saving the user clicks, and keeping them on their site.

Businesses who understand how to harness their own customers’ influence can make the leap from a few testimonials on a their About page, to a fan club spread across the web, where ever their customers and potential customers might be found.