I have a friend who runs a cat website, http://www.absolutelycats.com. The website is very successful and has been around for around ten years. It has built up a good amount of traffic over the years and ranks very well on the search engines. The only problem is my friend didn't take SEO into account with the site. Since it has been built, it's been hosted on a paid account at Tripod.com on a subdomain. Though there is a domain, it redirects to the subdomain. This is keeping the site from getting the high Google PR it deserves. To make things difficult, all its indexed pages are on the subdomain! I would like to help my friend out and get her page onto a real domain with a better host. The only problem is, I'm afraid she will lose her rankings and traffic if this happens. She can't afford to spend 3 months at the bottom of Google. Is it possible to move this site and convert the subdomain pages to a domain without causing problems? How can a loss in search engine ranking be avoided?
Wow, this is a tuffy. What I would do is try to get more advertisement to the main domain and slowly move some pages to the domain while keeping the index on the subdomain and slowly by slowly if you move to the domain I think you will keep your PR rating as long as people keep coming to the site. That is all that come to mind, but I hope someone gives you a better idea.
If you do not have control over the sub-domain (ftp access etc), then it will be very diffcult to avoid the effect (in terms of traffic, rankings, PR) in switching to a new domain. What I suggest is try to advertise you are moving your website to a NEW DOMAIN and also ask them to bookmark it. Plus try to shift the content of the old site to new site slowly so that new site builds up by the time new site is full of content. Also on your 404 error page mention clearly that this page has been shifted to your new domain. This way people would be educated and they will slowly move to your new site for reading or whatever. Slowly replace the menu links to your new domain on the home page as well so that Google follows ur new site and crawls and index it. Hope this helps.