Did the PageRank algorithm change?
What about the old domain? Do they take profit of old PageRank history? I see that very old domain have in most cases very high PageRank. I wonder why these domain still carry a lot of PageRank as the time change dramatically. Normally the rules should be changed a bit so that also new domains have a good chance for ranking. In the past, it was very easy to get good backlinks. Nowadays it is really tough as websites just reject to allow posting link in their comments or posts.