I’ve used these sites for some time.
The link you gave is the old version of the site. If you click on San Diego the San Diego page includes the definition of the listing area.
San Diego, California
Including Bonita, Chula Vista, Coronado, Del Mar, Dulzura, El Cajon, Encinitas, Escondido, Imperial Beach, Jamul, La Jolla, La Mesa, Lemon Grove, Leucadia, National City, Ocean Beach, Olivenhain, Pacific Beach, Poway, Rancho Bernardo, San Ysidro, Santee, Spring Valley
The new site http://www.housingtracker.net/
is now using Census defined Metropolitan Statistical Areas for monitoring Inventory and Asking Prices, and better metropolitan area definitions lead to better data.
Again if you click on San Diego it gives a definition:
San Diego, California
The San Diego-Carlsbad-San Marcos Metropolitan Statistical Area (approximation) has 25,534 total listings of which 21,960 are either Single Family or Condo. The area includes the major cities of Carlsbad, Chula Vista, El Cajon, Escondido, La Jolla, La Mesa, Oceanside, San Diego, San Marcos, Spring Valley and many others.
