I haven't heard this talked about anywhere else, but a client of mine notified me that his AdWords representative told him he needs to reduce the number of keywords within his new campaigns "to ensure that they do not place unnecessary load on our advertising servers." To be honest, my first impression was, that the client heard his AdWords rep incorrectly. Why would Google need to worry about "unnecessary load", these are paid ads, and the more keywords, the more money they make. To be stingy about large AdWords campaigns seems a bit ironic.
So I posted a thread on this topic at Search Engine Watch AdWords Forum. And in good AdWordsRep spirit, AdWordsRep replied to the thread with a confirmation of my beliefs.
As the number of advertisers has grown, and as a trend towards using truly vast numbers of (mostly untargeted) keywords was noticed, we decided to take proactive action.
I wonder how most AdWords customers feel about this...
