Google makes millions of dollars selling ads through their AdSense service. Their promise is that the relevant ads will automatically appear on websites with related content. In addition to that, Google and other advertising agencies produced ads based on your browsing history and tracking cookies. Here’s why those systems are ineffective much of the time.

Take a look at the page below. The ads shown on the page are being displayed because of keywords on the page that are being incorrectly interpreted. The advertisers are paying for these ads to be displayed, even though they are irrelevant to the content on the page, and less likely to be desired by the reader.

The title of the article contains the word “razor” and so an ad for a shaving razor appears at the top of the page. However, the article isn’t about shaving, nor is the title of the article. The use of the word razor is regarding a ‘razor thin’ (very close) result of a political voting outcome.

Below the title the text contains the word “race” and so an ad for racing tires are shown. Again, this ad is irrelevant since the use of the word race is not referring to auto racing.

The ads associated with the above article will change over time typically with each visit to the page depending on what other advertisers want to reach readers of the article.

When ads are properly placed next to relevant articles, such as an article about shaving and an ad for a razor, or an article about cars with an ad about tires, those ads are generally effective and valuable. In this case, advertisers are paying for premium ads but not getting them.

Here are some other reasons why smart ads are often ineffective, including ads based on your browsing history.

  • Irrelevant Items. Have you ever done a search for something, and then been blasted with ads related to your search? We’re not always interested in buying something related to a search. Maybe a family member had a question about shoes. You search and find the answer. You’ll now be seeing ads for shoes over several days. Advertisers are paying good money to reach you, and the ad system assumes you want shoes. But you don’t. So the ads are wasted.
  • Purchased Already. Have you ever seen ads for products or services you’ve already purchased? That’s because smart ads aren’t intelligent enough to know if you’re already a consumer of a particular product or service. They only know you visited a particular website.
  • Visited Sites. Have you ever noticed a flood of ads for websites you’ve already visited? You already know about the store or product, so the ad isn’t informing you about something you don’t know about. Other than the power of multiple impressions (repeated reminders) such ads aren’t very effective.

What’s worse, when people repeatedly see ads for something they aren’t interested in, they develop a negative feeling about your company or product.

For all of the reasons above, smart ads and targeted ads can often be a waste of money. You’re better off reaching people you know have an interest in what you’re selling. If you sell tents and sleeping bags, advertise in an outdoors magazine or use smart ads in social media where a person has already demonstrated an interest in something.