Flipping/owning internet real estate for passive income?

So I was putting in key words in Google to see what would pull up my blog (by the way "passive income project" now pulls up a couple of my posts on the FIRST page), and I found this cool little blog/site: http://www.netpassiveincome.com/

It pretty much tracks the deals of a passive income investor. He seems to be buying income-generating domains or highly-valued domains, increasing the monthly cashflow of those domains, then hope to sell them at a higher price while collecting on the cashflow. Sounds like a pretty cool idea, especially since brick-and-mortar real estate is not doing that well at the moment. I'm not going to jump into it right at the moment, but I'd like to do some more research and see how I can get in on this seemingly good business.