Since domain age is part of G's algorithm, has anyone noticed immediate SERP effects when a site reaches a certain age... 6 months, 1 year, 2 years, etc? Or, just a gradual difference?
I dont think domian age is a huge player, there are so many variables in the G algo that it is hard to tell a difference.
some keywords (Imo they decide it looking at the search volume) has filters up to 1-2 years , I had a keyword that I was nowhere during the year and ranked on the second place after one year.Backlink age is a factor on this point too besides the domain age.
To see signs of domain and backlink age factors you have to come to the web business after 2003 and you have to be in a competitive market. Otherwise you'll never feel it cause you don't have any filters on you , we have an proverb in Turkey that says " The full stomached man (I hope this is a true translation , correct me) , can not understand the feelings of a hungry man"
I think it happens in a stages. Here's why: When I started my site in April of 2006 (about 16 months ago), it got some fairly good Google rankings and traffic for the first two weeks (the new site effect), then most pages quickly fell out of the top 100 for their main keywords. After about 6 months, most pages made a sudden upward move in the rankings and then stabilized at their new positions except for minor day to day fluctuations. Then about four months later, they made another upward move and then stabalized again. Then there was another upward move recently, and a few of the pages have reached the top 10. So for my site, that's what has happened. The improvement in the rankings occurred in stages.