Does a site have lifecycle?

I found lots of sites ( here means micro amazon affiliate sites have 10-20 pages) lost rank about 6-8 months. I have three sites that have built about 4 months, which have 10 pages maximum, and haven't do nothing for them. No link-building, no more articles. In big G eyes, are they new sites or burn their life for a long time?

From what I know, the age of the domain counts for SERP. So the older the domain is... the better. Maybe your three sites are on a low competition niche!

I agree, domain age definitely makes a difference. I have many old sites that outrank my new sites because of this factor alone.

aged domain has some extent of significance .