When I first started online, I'd register domains that I thought I could develop and sell at a later time. After learning my way around the cloud, I realized many of the domains I'd registered are pretty much useless, or so I thought, and I let them expire. Come to find out several of these domains have been picked up by parking sites and are being offered for sale for thousands of dollars! Now I'm not saying they're actually selling for the asking price, but I learned my lesson. I never allow a domain name to expire. I add content to it, backlinks, some AdSense and try to sell it for something.
If you buy a dropped domain from Snap or Namejet, the backlinks seem to be worthless for SEO.  They are valuable for traffic if it's targeted to your site.  Go ahead and 301 redirect into your site because it's the traffic from the back links that is worth something.  I use the Google URL builder to redirect these names so you can see the domain the traffic is coming from.
You can find the new fields in the Column Manager and the Majestic Filter Tab. Majestic Crawled URLs, Information about the Outbound Links of the Domain and Information about the types of Incoming Links (follow, homepage, ...). Also you can now see the detected language for the website (or previous website) on the domain and the language of the anchor text links referring to the domain. The filter for the website language only includes values with at least 20% and the filter for anchor texts only with at least 10%. When you hover over the column, you still see all values (even lower percentages), but lower values are not used for the filter. If you only want to see domains matching the majority language, use the "majority language" filter. Unfortunately that filter doesn't work in the domain name search

1) pending delete auctions.  These are domains that were not renewed and are going through a pretty complicated drop process.  You can backorder these names at the auction venues and then each attempts to "catch" the dropping domain.  If one is successful you win the domain at $59 if you're the only one to backorder the name.  If more than one person backordered the domain a 3 day private auction is held.  Once the domain goes through the drop process, the back links have pretty much zero SEO benifit to the new domain owner.
Referring domains for anchor phrases usually reveals similar information. What you really want to look out for is whether or not the site has been picked up by a spammer in the past. A lot of times these expired domains were dropped, picked up by a website owner who then tried to rank it for keywords like Viagra, Cialis and whatever. You obviously don’t want that kind of domain.
In today's SEO (2015) the answer would be a big no! With changes to the google algorithm and the constant updates panda, penguin, what's next...., much of the "keyword url" power is now gone. While there was a day when it made sense to buy a good named .com and expect instant indexing, not so anymore unless the site is very strong coming in ,which in that case you'll drop a minimum $50k. If you are willing to drop that kind of money and the site has a high domain authority, it might make sense as long as it matches whatever product or service that you're trying to sell. Just my opinion...
Right now there are over 656,000 expiring domains that you can pre-bid on at Namejet. Lots of opportunity there even if more people come. The key is to find those hidden gems and wait until 1 minute before they go off the board (assuming no one has bid on it yet) and then bid. This is the best way to attempt to be the only bidder on a domain and win it for $69.
In the grey hat SEO world, the thought is that you can take a domain that is keyword driven, do a quick optimization to get the site ranking, and sell it off at a profit. It could, and does happen daily. How much time is invested in optimizing a site to get to page one, vs how much the site will sell for? (remember that quote at the beginning of this article?). Let's put it into simple math:

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.
Aside from places where you buy and sell domain names, there are some companies around that support the business of domain flipping. GoDaddy is one of the bigger names out there that does. There, you can not only trade domain names but also park those you’ve bought. The buying, parking and selling is relatively painless and all you must give up is a small percentage of your selling price.
Yes, we port in all of the domains from NameJet, SnapNames, etc. There are a lot of great deals to be found. Some are absolute trash of course but if you can sift through them and put some time in (hopefully that is what we are trying to do with our tools is save time and give some value add with the SEO metrics, alerts, etc.) then you can find some great bargains.
Contains, Starts, Ends You can use the search bar to search for domains that contain particular keywords you are seeking, e.g. a search for "car" will yield results for all expired domain names that contain the term "car". You can also use the search tool to find domains that begin, or end with the search term too, with the drop down box next to the search form.
What if we replace “bitcoin” with “ripple” in all these examples? SellRipple.com? RippleGiftCards.com? Ripple.network? Ripple.us…etc. You get the picture. There are a 100 of these on NameBio + the keywords we got from the Google Keyword Planner, that’s hundreds of potential high-value domains right there. The thing is, we’re only scratching the surface here. According to Wikipedia, there are over 1,300 cryptocurrencies online as of January 2018.