What about option #4 - Redirect your existing domain to the old domain? I bought an old domain that is 100% relevant to my current domain but currently has with very little content. It did have more content fours years ago. The old domain is 13 years old, pr=3, while my current is 7 months old pr=1 and a decent amount of content. The old domain I purchased was not expired though and I do not know if this makes a difference. What are the pros and cons of option #4? Am I correct to think that option #1 would result in no benefit from the old domain's age value and if so why is it not listed as a con, a MAJOR one. Its hard to believe that a 301 using option 1 would give my existing domain 13 years credit but I'll take it if it does.
Your course of action really depends on how much work and effort you can put into the expired domain. If you're barely able to maintain and optimize your current site, you probably want to just 301 redirect the old site (note: see my amended comment above about the link value not likely to be passed). If, however, you're more creative and have some time on your hands, you can try your hand at crafting a microsite. If you really know your stuff and are experienced at making money off various websites, you'd probably do well with the third option.
As an Internet marketing strategy, SEO takes into account what people search for and how search engines work. Optimizing a website may include editing content, HTML, and associated coding to both remove barriers to the indexing activities of search engines and increase its relevance to specific keywords. Another SEO tactic is to promote a site to increase the number of inbound links (also known as backlinks).
2) prerelease auctions. These are domains where the auction venue has contracted with the registrar, like Fabulous or Moniker, to auction off non-renewed domains. Just before a domain enters the pending delete process, it goes to a private auction to any person who has backordered the name. Some people feel that back links on these type of auctions still provide a SEO benifit. My testing indicates that there is zero SEO benifit when these domains are redirected into another site. So if you get a domain with "pink squirels" in a lot of achor text to a domain and then point it at your domain, you don't rank for "pink squirels"
ExpiredDomains.net gathers all the information you need to find good Expired Domains that are Pending Delete and you can Backorder. Depending on the domain extension you can search through thousands of domains every day before they get released to the public and pick what you like. ExpiredDomains.net currently supports 473 TLDs. From the classic gTLDs like .com, .net, .org to Droplists for ccTLDs you can only find here and now we even support some of the best new gTLDs like .xyz and .club.