Below is an excerpt from a press release from the National Auctioneers Association.  It references an industry trend study that NAA conducts every year.  This is from 2005.  2006 numbers are not in yet.

According to the NAA’s study, auctioneers found opportunities in real estate. Gross revenue from residential real estate auctions grew 8.2 percent compared to the same time last year. The value of all residential real estate sold at auction in 2005 is estimated at $13.1 billion. While revenue from commercial and industrial real estate auctions and vacant land and agricultural real estate auctions remained largely unchanged, real estate auctions remain on pace to top $48 billion in gross revenue for 2005.

While the amount of real estate sold by auctioneers is well behind the amount sold by Realtors, more sellers are looking to the auction method to sell their property.  Quite a bit of this property is sold with Realtor participation and from Realtor referral.