Amazon announced this week that it's suing more than 1,000 people who were offering to write fake reviews for pay online. It's a big problem for the retailer, as well as sites like Yelp, and research has suggested that as much as 20 percent of reviews are fake. 

Given so many of us depend on reviews to help us choose our purchases, how can we shop smartly? David Lazarus, who writes the Consumer Confidential column for the LA Times, explained why Amazon has gone after the fraudsters, and gives us ways to outsmart them.

To listen to the full interview, click on the blue audio player above.