How I would do it is have each client setup and use their own Google account and their own Adwords accounts. You can then manage their Adwords accounts using Adwords MCC (my client center) and add their websites to analytics. So with just one (or maybe 2, depends how you've setup) Google account for yourself you can log in and manage all of your clients adwords accounts and view analytics for all of their websites. Your clients will also be able to manage/view their own Adwords accounts and view reports for just their website on Analytics. You'll need to setup user access in analytics etc.
So basically one Google account for you, and a Google account for each client, that's how I would go about it anyway. |