I heard this term for the first time from Dustin Luther's NAR seminar titled "Understanding Your Online Competition".  He was referring to the fact that an online presence is all about hyperlinking to and from as many sites as possible.  Obviously its a play on the most important thing in real estate which is location x3. 

I thought it was catchy enough to pass along. 

And speaking of the November '07 NAR conference, (yes we bought the MP3s) the panel that Google and Zillow are on is a good one also.  Zillow talks about a coming soon service called Virtual Sold Signs - and they were right, it's here now!  Have you added yourself to all of your sold listings yet?  What a good way to be viewed as an area expert, especially if you have a large portion of the market share in any particular neighborhood. 

My humble opinion is that Zillow seems to be making progress on shifting the REALTORS perception of them.  Two years ago at our office meetings agents were cursing Zestimates, now REALTORS are happy they have a free place to market themselves.  Well done Zillow.