This is a little bit on the grey hat/black hat side of the spectrum. But the fact is building a blog network with expired domains flat out works. The only issue is getting those cream of the crop domains without going broke. This video will walk you through tested strategies and techniques you can use to find powerful, yet affordable, expired domains.

I've fixed some speed related problems and the new search cluster is now live. The combination of both speeds up every search noticeably. Also some unfinished expired lists are no longer in the domain name search. Some users noticed that you could already find TLDs in the domain name search that were not released yet. This is not possible anymore, however if you are one of those users, contact me. Let me know what TLD you are interested in and I will prioritize it.
Use escrow services for direct sales. When you are dealing directly with the buyer, make sure that any money that is transferred goes through an escrow service. This will ensure that all checks clear and that you aren't left with a bounced check and no domain. Escrow services may add a few days to a sale and cost you a percentage, but they can save you a lot of heartache.
Using the keyword search feature you’d also be able to familiarize yourself with how much domains typically cost on average in a certain industry or niche. Even better, they have an addictive little app called “The Domain Game” available for iOS and Android. They basically give you a domain and you try to guess whether it sold for three, four, five or six figures. You get points for each correct answer and lose points for incorrect ones. You do this for a while and you start to see patterns. Your brain starts connecting the dots and you get better it. Now you’re ready to go out there and scout some domains!

When the domain drops, the minute it drops, literally, they will try to get it and if you can get it, it’s yours. So, that’s it for expired domains. You can see it’s a little bit complicated and it takes some leg work, but if you’re interested in building a publisher network or a private blog network, this is a great way to find sites that have a great link profile without you having to actually build any links. So, that’s it for this video. I’ll see you in the next one.

Check DA/PA: The “Domain Authority” and “Page Authority” metrics gained significant popularity over the last few years. They seem to correlate well with a domain’s ability to rank in the search engines and hence, a domain having a high DA/PA will typically have a higher value. This is not to say domains with low DA/PA can’t sell for a lot of money because, at the end of the day, it’s just one factor. However, it’s good to take a look at these as they may tip the scale in favor of or against some buying decisions.
Park the domain with a domain parking service. Since you may not have content to put on the site, a parking service puts up a dummy page with ads. When people visit and click on the ads, that's money for you. This method works best with popular keyword domains that get lots of traffic. In most cases, you will not have control over what ads appear on your domains.[5]
Link popularity: the link popularity is a parameter that is used to quantitatively evaluate incoming links to a website. This is measured depending on the number of links to a domain according to the mantra 'the more incoming links, the more important the site'. Link popularity is generally determined by the PageRank algorithm. The PageRank only plays a minor role in determining the domain’s relevance.

If you buy a domain from a 3rd party, the backlinks are valuable.  I always wait a few months before redirecting, so just set up a quick minisite until two page rank updates have passed and then go ahead and 301 redirect.  However, it seems that you'll get the link juice from the back links, the anchor text is ignored by Google.   Buying a domain at Godaddy TDName expired auctions, seem to not count as a dropped domain if you immediately set up a mini-site.

Domain names expire when someone decides to stop renewing it. They may not be available to register immediately. We update the search index every night, so some names may already be renewed or re-registered. Some may become available in a few days. Some registrars, like GoDaddy, will let you buy a name that one of their own customers expire immediately. When you find a name you like, just click on it to try backordering the name!
You can’t tell us (with a straight face) that aged dictionary word .net and .org domains won’t sell easily. The .net extension is technically OLDER than .com, and holds an equally intrinsic value to that of its .com counterpart. These LLLL .com’s that are just letters slapped together may be cute to look at and easy to sell, but in the eyes of Google, ANY aged domain that makes sense (i.e. a dictionary word) is going to be much easier to rank for than some acronym or hodgepodge .com…and at the end of the day, that holds more value than whatever society sees in these nonsensical “” names.

Many non-savvy internet users may not even be aware of the existence of other extensions. That said, because there are many new extensions popping up every now and then, you can often find amazing one word and 3-letter domain names with these new extensions that are otherwise almost impossible to find unregistered in the .com world. Additionally, these new extensions are becoming more and more familiar to users every day, hence it's almost certain that their value will continue to increase as time passes and wider adoption manifests.