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Yeah... you'd probably want to redirect those offline advertising URLs depending on the device being used.  Unless your site is primarily mobile, you'll probably want to distribute your regular URLs in offline advertising, not URLs with mobile.example.com. For usability, you should have links to go between the two version of the site.  What would be even better is if you did this: set a cookie when you change the version of the site you're on, to prevent the redirect in the future.  So if you change from the default version of the site from the version that we think you would want for your device, and come back to that site later, we'll use the version you selected. For example, if a user prefers the desktop version on their iPad, the first time they go to your site it'll take them to the mobile version.  Once they click the link for the desktop version, they'll always receive pages from the desktop version of your site (for 1 year unless you renew the cookie or they clear their cookies).  This will work even if they click a new link to your site from search result pages.