I have a client with two 4 year old domains. He's been using one for his site, and has backlinks built to it.... but it's a ugly name. And the rankings have dropped a bit lately. The other he uses for the company's email and has had it parked with Godaddy for 4 years. But it has a MUCH better name I think. Also he's gonna redesign his site in a month or two with all new sub-domains, so he'll lose most of his rankings in his sub-pages anyway I think. I can do one of two things. Keep the current domain and 301 the better named one to it and just keep on going like normal. Or I can change him over to the "un-used" 4 year aged domain that's been parked for 4 years and then just 301 his current site to it. Site 1: Ugly name, been getting used by him for 4 years, seen some rankings drop lately. Site 2: Good name, been parked and used for emails for 4 years.