If you have multiple ad variations within a campaign, are they all rotated - even if the variations are to different display and destination URLs? (i.e. the ads are not displayed at the same time) e.g. if you have one ad for "example.com" and another for "example.net" in the same campaign for the same keywords, would they always display exclusively (so you need a new campaign for each site), or can they show up together for the same search?
Only one of your ads (per adwords account) will display for a query. So if you have multiple campaigns or ad grousp that are biddig on the same words you won't have multiple ads diaplyed in the search results. Check out the adwords learning center.
Thanks for the reply. So one cannot advertise mutliple times for the same phrase even if they are promoting different things? Interesting.
That's called double serving and isn't allowed. See this - https://adwords.google.com/support/bin/answer.py?answer=14179
Some time ago you could request an exception if you are promoting completely different business, don't know if is still available. but I never hear about someone that has been approved.
Wait - so what do the big PPC service firms do? Surely they must deal with overlapping keywords for different clients? I guess it's just tough luck for them, and the clients.
Indeed Google says on the page linked above that they do not allow multiple accounts for this purpose. That's why I wondered about the PPC firms. Now I wonder if they would really bother to shut an account down for this reason, let alone both accounts, but who knows. It's probably not worth the risk.