For the following TLDs you can now find a expired/deleted domain list. .cr, .gd, .gs, .im, .ke / .co.ke, .kg, .kz, .ir, .la, .ma, .pe / .com.pe, .pm, .re, .tf, .wf, .yt, .so, .th / .co.th, .uz They also show up in the Deleted Domains (last 7 days) list and in the Domain Name Search, however they are not in the pending delete list! I do not have a working droplist for them yet, so that is why they are not released in the pending delete list yet.
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:
The market-driven principles of the domain trade mean that a domain is only worth as much as the buyer is willing to pay. It is for this reason that criteria such as market potential and usability play such central roles in determining prices. Values can change immediatly and without any warning. The price of a domain that was once of little interest to anyone in years past can skyrocket once, for example, a newly founded company takes interest in that same name.
However, I'd argue that most people in the business really struggle as they don't understand what makes a good domain name and what's a bad domain name. While I do not work in this field full-time, I can say that I can make a living of it, but it's probably because I don't ask for absurd prices (e.g. randomword247.com domain name for $8000 is just unrealistic and won't happen) and therefore can sell domains easier.
Surely if you purchase a domain (domain1.com) and redirect it to your existing domain (domain2.com) you expect to loose all ranking for domain1.com. If 301's are used then the objective is simply to pass on authority, not dominate the search results with 2 domains. If you want to keep domain2.com in the index then you would take Rebecca's option 2 or 3.
Whether you can use an existing backlink profile for a new web project under the available domain depends on whether the link target of incoming links can be reconstructed. In order to analyze which content was provided under a domain in the past, you can find out on the Internet Archive Backlinks have no value if they lead to nowhere and this can even have a negative impact. They are possibly redirected to similar subpages or homepages using 301 redirect. In this case the most part of the link’s power is lost.
Length: This is pretty self-explanatory. Generally the shorter the domain name, the more valuable it is. This difference in value decreases exponentially as the name gets longer, though. For instance, the difference in price between 3 and 4 letter domains are significant, while the price difference between a 7 and 8 letter domain would usually be much less significant.