We all know links are what make our websites popular. And active website owners and webmasters spend (or should spend) good portion of their time building links to their websites to increase their websites popularity and ranking.
So most search engine optimization consultants, put much of their focus on two major factors
1. Quantity of links
2. Quality of links
It is observed that a well ranked website needs to have good number of good quality links but also as part of natural link building strategy, each good quality link should naturally go with a few low quality links. And with low quality I do not mean spam links I mean links from low PR websites or sites with few or no back links including a few nofollow links.
But another important factor that unfortunately doesn’t get enough attention from SEO consultants is link age;

Link age is important for two main reason:
1. It can show Google (and other search engines) the freshness of your content; It makes perfect logical sense that new links could mean new fresh content. So if you have a website that you update content often, you want to make sure you match your fresh content with fresh links.
2. Link age shows trust: Search engines in particular Google care about age of links to your website because that shows the links are legitimate and it is editorial rather than artificial.
Google in particular puts good focus on website trust and authority hence the longer age of a link the better trust ranking you get from that link. Keep in mind that currently trust ranking is not public by Google but you can try to figure out your websites trust ranking by checking your keywords ranking. If your ranking is relevantly stable, with exception of a few drops, then Google trusts your website. But if you your ranking keeps dancing, then you need to keep working on establishing trust with Google. I wrote an article on Google authority and trust rank back in May you may find interesting.
So don’t forget to take link age into an account when you are optimizing your website. Yes you do need links, because fresh links mean freshness of your content and vote for those content but you also need to consider link age so put your link building efforts into links that last.