This topic has already been addressed in "How To Buy A Home For Sale By Owner" on Ezine@rticles.com. There are however a few interesting stats that beg an update.
The most current Profile of Home Buyers and Sellers from the National Association of Realtors® found that fewer than 1:5 buyers search the FSBO dot com Web sites. Additionally, only 9% of the homes offered for sale in 2010 were FSBOs, and 88% of the homes that sold were Agent-assisted sales, 5% were sold to someone the seller knew and the remainder were sold to others.
Anecdotally, it's worth noting that FSBOs seem to reach the desperation phase somewhere between two and three months, and represent a virtually untapped resource for buyers. They are not easy prey though, at least not for most buyers. Reading the original article should help, but will not be a 1:1 substitute for a seasoned professional buyer's agent.