This just in..Google is monkeying with the number of ads on certain pages of search results…more on some, less on others. That’s what they’re saying in Google’s AdWords blog.
We constantly evaluate how our users interact with the ads we display and look for opportunities to show more ads when we think they’ll be useful — and fewer ads when we think that users might not want to see them. With this in mind, on queries such as ‘car insurance’ or ‘flowers,’ we try to show a wide selection of relevant ads to our users. And, for queries where users are most likely not interested in a product or service, such as ‘dog friendly parks in Mountain View,’ we may aim to show fewer ads.
That actually sounds good. Sort of. I don’t understand why they wouldn’t want to show ads with dog-related keywords. Isn’t that demographic (e.g. dog owners) targeting?
Then I almost missed this one:
If you notice a decline in impressions or clicks on some of your keywords, you may wish to ensure that your most important terms are each specifically entered as keywords in their own right, rather than relying on broad or phrase match to include them. Or, if you notice an unwanted increase in impressions or clicks for some keywords, consider adding negative keywords to more finely tune your targeting. [Emphasis added]
If I didn’t know better I would think that Google is trying to drive up bids on the more specific (and less searched) keywords, making it more difficult to find cheap keywords to buy.