In my experience, it is not a matter of decreased efficiency of the keyword, but rather decreased efficiency of the management of the keyword.
If you have the resources to go into each of the separate campaigns and see how the keywords are performing then it is a worthwhile venture.
The real benefit of "geo-targeting" keywords comes from improved ad copy. You will be able to display French ads to the French searchers, and English ads to your English searchers. The one caveat is that if you do break it out and target a different language you will need to have content in the language you are targeting on your web site both for quality score and conversion purposes.
|