Cars.com allows users to Favorite any vehicle which then provides price alerts and removed posting alerts if any ad falls of the site.

 
 
 

MyAlerts works as an integrated part of their customer signup/sign-in process so it's a seamless integration, but returns users back to their site with every changed ad.

 

Price Drop Alert

Sold Item Alert

 

 
 

See how HomeAway allows their users to save vacation property alerts when they are seeking locations, dates, and other criteria that helps bring their users back to their site 10x more than before.

 
 
 

MyAlerts monitors the site for new listings matching that users search criteria and sends them new property alerts branded to HomeAway.  This also gives them insight to the demand for more properties and listings their users want in the future.