Google has made a slight change in their Adwords display URL guidelines which will affect those of you who use hosted domains. The full guideline can be found here: adwords.blogspot.com/2010/01/policy-adjustment-for-display-urls.html Basically, if you have a site that is shared on a domain (good example they use is blogspot.com) and want to advertise it with Adwords, you now have to include the sub-domain in the display URL such as: myblog.blogspot.com Starting next week, your ad will be disapproved if you don't to this. So be proactive if this affects you.
How is this bad for adwords users? Its definatly good for searchers since they know where they will be going. Its good for advertisers since the client is more likely to click on a sub-domain with their keywords in.... Its only really bad for adwords advertisers trying to do something a bit dodgy and send clients where they may not be expected to go, which is a breach of the adwords guidelines anyway.....