Every single day since 2014 I log onto DomCop.com and find valuable expiring domain names. Literally. I've found so many great domains there that I've either put into my domain investing portfolio, built on and created a revenue generating site that I later sold. I cannot recommend this tool enough--it is robust and powerful, and I easily filter out the thousands of terrible expiring names to consistently find the diamonds.

Sean Markey, Rank Theory