The biggest advantage of using expired domain names to earn cash online is that they belonged to a website that had already establish, registered with several search engines companies and has existing backlinks and traffic. In general, by making use of expired domain names you tap into the resources that were created by someone else to get rich within a short time unlike when you do all the dirty work to get your website recognized immediately.
You can add it as part of a private blog network or you can 301 redirect an expired domain to your site to bring some trust and authority to your site. Now, in my experience, the best place to look for expired domains is this free website called expireddomains.net. So, you just have to head over there, make a free account and this is the page that you’ll see when you log in.