The Television Bureau of Advertising, a local TV trade group, says GM is missing a great opportunity to build its brands because the automaker moved away from spot television ads to digital ads online. No surprise there. For the past three years, GM has been moving more of its ad budget to targeted audiences online. This is a rifle approach, aiming at consumers in the market to buy a new car. On the other hand, TV, while still important, represents an expensive shotgun approach.