Not content with dominating online advertising Google has announced that it has started a trial in America to do the same with television advertising too.

Teaming up with EchoStar and Astound Cable in the US the company is to trial television advertising in a similar way to how it offers online advertising.

Would-be advertisers will be able to upload adverts to the company's website and like the current AdWords system, customers will buy Google TV ads using an auction model.

Advertisers can target by demographic, daypart and channel and pay only for actual impressions delivered. Pricing is on a CPM basis.

According to Google due to advances in set-top-box technologies it is possible for them to report aggregate statistics on how many times an ad was viewed and whether it was watched through to the end.

"Advertisers can use this data to understand the effectiveness of their TV ad campaigns and use this information to provide more relevant ads to viewers", the company said in a statement.

If the trial is successful it is likely to rolled out to other networks.