The better quality links (From Google, Wikipedia) that a website has the higher will be its domain authority. New websites start with a ranking of one, and as the number of links increase the domain authority rises. For example, a sports website that has links to sports newspapers and sports reporting sites will have a higher domain authority than a sports website that only has links to other sports and sports blogging sites.
The second option requires a bit more time and effort than a 301 redirect. You could do a mini overhaul of the site and turn it into a microsite for your main domain. This option is good for exact-match domains for your targeted keyword, and there are other reasons for going the microsite route that Rand's highlighted in his post about root domains, subdomains, subfolders and microsites. This strategy also works better if the old domain has decent rankings for the keywords you're targeting.
The great thing about this is that it’s kind of like a metasearch engine for all the places that you can find expired domains around the web. First, let’s look at deleted domains. Okay? To do that, you go click on the deleted domains button here and then click on any top level domain that you want to get. I prefer .com because it’s obviously the most common top level domain.
Thousands of domain names expire every day. The reasons are different. Some owners forgot to renew the domains, some just don't want them anymore or they moved on to other projects. For most people these so called Expired Domains don't have any value. They just see a bunch of Domain Names someone else deleted and move on, but for the people who know about SEO or the value of good Backlinks, Expired Domain Names are money just waiting to get picked up from the street. The only problem is to separate the good ones from the bad ones. That is where ExpiredDomains.net comes into play.