Google has created a new set of rules for their adwords program, which bring them 98% of their revenue.
The rule is displayed in adwords help
When you create your ad, you’ll also specify a destination URL, which is the exact URL within your website you want to send users to from your ad.
This is translated below
If your adwords spend < $10000/mo the display URL must exactly match the destination URL.
If your adwords spend > $10000/mo you can use any URL you wish
So these rules indicate you cannot have a website www.my-site.com and a display URL www.mysite.com
Here is one example of the Google Adwords display policy in effect
Disney is using the display URL: www.DisneyVacationClub.com which redirects to www.dvc.disney.go.com
See the query here