I want to switch an established site to a domain that has a full keyword in it and redirect the old domain. What is the safest way to do this and not get the duplicate content penalty for having 2 domains?
work on the right redirect, try to switch all the links, remember it won't be easy but it will pay off.
well first you want to think of your established site as being an established domain name as far as serps go. If you do a primary domain name change then you are starting from scratch as far as serps go. perhaps viraly you will be fine but most likely lose pr and definatly loose serps. If you do a 301 redirect then you will have all the seo efforts redirect to the new name but for me this only worked temporarily. I did this on a few domain names and I personally have had bad experiences with my dn that had all the PR and serps compeltly loose its pr once I redirected it. You could send an email to everyone that is linking to that domain name and ask them to link to this new one instead. That is pretty tedious but could be a good solution. These are things you need to weigh out. I recently did that with a site that was ranking ok and switched it to a more keyword rich dn. Its taking time because its still sandboxed but I am hoping that once all my seo efforts are done the site has a much higher ceiling then the last dn did.
When we do exactly what you're thinking of doing for our clients who either want it done... or we recommend it be done... it's a tedious and slow process. Doing it haphazardly or incorrectly will absolutely kill any seo efforts and ranking effects previously acquired. I'd be very, very cautious doing it yourself.