I have a client who purchased a new domain for a project he plans on launching in a year and a half or so. He wants to improve the domains age before he actually uses it for the launch and is thinking about simply putting it up a dummy site of sorts (or maybe a page that says "coming soon") to build the domains age. My assumption would be that the site would have to be at least semi-active for it to gain any SEO equity for domain age. Or does it just have to be crawled occasionally? Anyone have any experience with this?