Popularity sells.

Carl Bialik's article in the Wall Street Journal on the influence of Top 10 lists questions the wisdom of crowd-sourcing, but also highlights a proven tactic that marketers should consider to help drive incremental sales.

Popularity metrics abound online: Top 10 emailed stories on wsj.com. Most downloaded songs on iTunes. Yahoo's Top 10 user searches. Studies show that people decide what to do in part by following others. We are pack animals at heart, finding comfort in the herd.

Bialik's article cites instances in which marketers were able to dramatically shift customer preference and behavior by calling out those items and choices preferred by other customers.

Amazon has employed this successfully over the years ("people who bought this book also bought..."). However, Amazon makes this recommendation after you've made your initial selection. The dynamic Bialik reports on is the influence popularity has on the initial purchase decision.

I could see ways of applying this to many different categories. Ford dealers could post a sign on the roof of a Fusion letting me know that 63% of current Fusion owners bought the new Fusion. Best Buy could let me know that 57% of people who bought this flat panel combined it with this blu-ray player. United could tell me that 68% of people booking the JFK-SFO flight I'm considering purchased a one-day Premier Travel Option.

Timely and specific suggestions of what similar customers prefer can lift sales. How do I know this? I heard other people saying so.