Problems with Google's AdSense

I just spent some interesting but ultimately fruitless minutes looking for a particular blog entry I saw somewhere a few weeks ago. It was on a scientifically-oriented blog of some sort (like The Bad Astronomer) that had Google AdSense ads on it. What struck me at the time was the irony of the fact that the particular posting on that page was a rant against some pseudo-science while AdSense provided an ad for a service based on exactly that pseudo-science. That got me wondering how often it happened that an ad was diametrically opposed to the content of the page it appeared on. So I tried a very small experiment. I got onto my Gmail account, and sent myself a message containing the one line:

This is a rant against water dousing and water witching.

When I read the message in Gmail (which also shows AdSense ads), it showed these four ads over on the right side of the page:

New Winner Every Day
Win 5 Pet Peeves Characters(tm) Enter the Free daily Contest here.

Pendulum of Pendulums
Dowsing results you can trust -free shipping

Spiritual Dowsing
Beautiful Pendulums & Great L-rods Dowsing Books & Dowsing Services

Innovative health product
Preventive, non-invasize technology Subtle Energy Technologies

As you can see, two of the ads are exactly for services based on the pseudo-science I mentioned in my mini-rant. I tried the same thing again using different text and, as I expected, got essentially the same outcome. Google searches (upon which AdSense is based) are very effective for finding matches for words and phrases such as those that occur in a blog page or an email message. The problem is that AdSense cannot distinguish between positive and negative mentions of these terms. (BTW, I have no explanation for the 'Pet Peeves' or 'Subtle Energy' ads.) So, the moral of the story is:

If your page uses AdSense, and it is showing ads you don't like, try changing the wording of the problematic phrase, or try rendering it in some clever way that human readers can easily read but which AdSense will not pick up on. For example, space the p r o b l e m w o r d s out.