The official Google adwords blog has notified that starting from 24th February 2009, Google will implement a change to their current AdWords policy in regards to having multiple display URL domains in a single ad group.
Emel Mutlu, Inside AdWords crew writes:
In an effort to provide more relevant results and a high quality experience for our users, we’ve made the decision to disallow multiple display URL domains within a single ad group. Going forward, all display URLs within an ad group must have the same top-level domain
Which Advertisers will be affected by this change?
Advertisers who are using multiple/different display URL Domains on the same Ad Group on a campaign will be affected. So for instance, if you have an Ad group (i.e. Ad Group 1), with many different kinds of Display URL of one single domain that you are likely to be safe.
So the following Display URLs would be fine for a particular Ad Group:
However, if your Adgroup has display URLs showing multiple domains then you will be affected by this new change in policy.
For example the following Display URLs won’t be accepted, if used under one single Adgroup:
example.product.com (The Domain here is different – Product.com. You can only use ONE domain per Adgroup)
What should Advertisers Do?
If for some reason you need to have multiple domains in the Display URLs, you can simply create a separate Ad group for that purpose. Just make sure that you don’t have different display URL domains on a single ad group.