Hi, I have a classifieds website and would like to optimize it. The issues/questions I have: A Classifieds site has, say, 500 cities. Is it better to create separate subdomains for each city (http://city_name.site.com) or subdirectory (http://site.com/city_name)? Now in each city, there will be say 50 categories. Now these 50 categories are common across all the cities. Hence, the layout and content will be the same with difference of latest ads from each city and name of the city and the urls pointing to each category in the relevant city. The site architecture of a classifieds site is highly prone to have major content which is not really a duplicate content. What is the best way to deal with this situation? I have been hit by Panda in April 2011 with traffic going down 50%. However, the traffic since then has been around same level. How to best handle the duplicate content penalty in case with site like a classifieds site. Cheers!