From the NY Times.com The future of the 30 second spot .
I pulled out some relevant lines, to read the whole story click above.
The television commercial - a blunt instrument that often reaches as many disinterested people as desired ones - is beginning to behave like a smarter version of direct mail. Ads can be customized, not just by neighborhood, but ultimately by household and perhaps by viewing habits.
Marketers recognize the need to tailor their messages to different, more finely calibrated audiences.
Time is running out," said Eric Schmitt, senior analyst at Forrester Research and the author of a recent report called "What Next for TV Advertising?" "At some point, it's going to be impossible not to acknowledge that the medium is overvalued as an advertising vehicle."
But there is little evidence that product placement has bolstered sales. If anything, measuring its success is even more difficult than gauging that of a 30-second ad. And few companies can afford an entire season of "American Idol" the way Coca-Cola can.