Real-time advertising offers unprecedented precision

The old saw, "half my ads work, only I don't know which half" may soon not be as true as it once was. In yesterday's marketplace, companies tried to target their ads by choosing the television shows, magazines and other mediums that had demographics most closely resembling their target audience.  But the measurements were crude, and billions of dollars were spent putting advertising in front of people who had zero interest in the product.  If you lived in an apartment, advertisements...