MOUNTAIN VIEW, CA: Internet giant Google is trialling the dynamic insertion of television ads in Kansas City, with subscribers to Google Fiber TV getting the first taste of the service.

"Fiber TV ads will be digitally delivered in real time and can be matched based on geography, the type of program being shown (sports, news, etc.), or viewing history," the company explained in a blog post.

"If you're a local business in Kansas City, just as with digital ads, you'll only pay for ads that have been shown, and can limit the number of times an ad is shown to a given TV."

Viewers will notice little difference, however, as ads will be shown during existing ad breaks along with national ads. The viewers are also being offered the ability to opt out of being shown ads based on their viewing history.

The Kansas City Star elaborated, using the example of a Kansas-Wichita State basketball game, which typically attracts a broad range of viewers.

"Imagine placing ads during such a high-rating event that recognise one viewer spends several hours a week watching kitchen shows and might be a sucker for an ad for knives.

"Or others, glued to the same basketball game, who see a motor oil ad because they watch five hours a week of auto racing."

One area of particular interest is that ads can be inserted not only on live TV programs but also on those recorded on DVR.

Or, as Advertising Week put it, "if you save Sunday's Walking Dead until Wednesday, you might get ads for a sale at the Oak Park Mall that starts on Thursday".

Advertising Week also quoted a source familiar with the deal who said "the tracking at this point is pretty unsophisticated", as Google is proceeding cautiously to avoid any possible privacy infringements.

So, while there will be direct measurement of viewers in order to enable payments by advertisers based on how often an ad is shown, viewers are not being further matched with other data sources.

Data sourced from Google, Advertising Week, Kansas City Star; additional content by Warc staff