I have a regional service-based business where I have enjoyed a rank of #1 or #2 for a highly competitive keyword for several years. I regularly update the site with new unique content. Site size is about 800 pages. We are emphasizing a new service offering and I though that it would be a good idea to launch a second site, which is complementary to the main site, to focus on promotion of the new service. It has been about 3 months since the new site has been on-line and I see a drop in my rank of my main site for multiple keywords (position 1 dropped to position 6 for the highly competitive keyword,as one example). I realize now that almost all the content on the new site is basically 90% or more duplicate to the main site. I have taken down the new site. How long will it take for Google to register that the duplicate content has been removed, as a result of taking down the new site? Should I expect the rank of my main site to pop back to where it was? Is there anything else that I should keep in mind (other than to never do this again)?