I personally own about 50 domain names...most that I bought with the intention of using for a specific project that never materialized. With a handful of them I paid a writer in the Philippines to write a dozen articles for each, and I threw together simple wordpress sites with RSS autoposting and they make about $10/mo each, which pays for the renewal fees for all of the other domains.
I suppose in theory I could register 1000 domain names and repeat the process of paying for content, setting up wordpress RSS autoposting, and possibly make $10,000 a month, but I never seem to get around to it, and there's the possibility that it won't be as profitable as I think.
That's what this kid is doing with 500 domains.
Here is an example of the content I paid someone in the Philippines to write: http://www.techspyer.com/tag/digital-camera/ (most of the tags have a "buying guide" at the top)
All of the "posts" are just coupon feeds from Linkshare's RSS feed. This site made $10-15 per month for a solid year. The total cost is as follows:
Domain: $7.49 (GoDaddy)
Hosting: Free (Unlimited accounts on Rackspace)
Content: $24 - $2/article x 12 articles
SEO: $10 in backlinks from SubmitEdge
For the other sites, I prefer to keep those private because they are in untapped niches and I don't want to invite competition, but for those I focused on content RSS feeds and AdSense instead of affiliate links and they make about the same amount of money per month.
I'm going to try to do some more of these sites...I keep telling myself that if I registered 1000 domains and put simple sites like these on them at $41 each, I could turn $41,000 into $10,000 - $15,000 per month. Of course the hard part is getting started.
where are you buying content for $2 a piece?