I've never understood why agents are so willing to help other websites outrank them. Then one day it occurred to me that these agents didn't actually understand what they were doing!
No agent in their right mind would ever link to a competitor, they didn't know that by placing those pretty little widget on their sites they are actually sending "Google Link Love" to their competitor. Yes, Zillow, Trulia and Realtor.com are competitors. They take our information and sell it back to us for a price. Worse yet they offer widgets that link back to their sites and tempt us to use them but never really disclose that they are using them against us.
Look at this widget, published today on Agent Genius. Once you understand the meaning of widget spam, I bet you will think twice about using those pretty little widgets. Even if you decide to go ahead and use them, it least you will know they can be Hazardous to your SEO Health!