Data on an internet user in one place can be analysed in another, then used to sell advertising, aimed at that user, to an advertiser in a third place.
The trend is particularly noticeable in advertising aimed at children.
The agencies are McCann Erickson Worldwide, for advertising aimed at the general market; Casanova Pendrill, for advertising aimed at Hispanic consumers; and GolinHarris, for public relations.
Consumer protection laws were enacted to regulate product safety and advertising aimed at children.
In 2008, Obama put more of his money on advertising aimed at Republican-leaning audiences.
She said that their commercial efforts, particularly the advertising aimed at children, could be crass.
Last year, makers of sleeping pills spent more than $600 million on advertising aimed at consumers.
Regulators have become increasingly concerned about advertising aimed at children online.
The A.P. is, for what it believes to be the first time, running advertising aimed at consumers.
Still, it is not easy to design advertising aimed at senior citizens without making them feel like relics.
The Clintons suggested they would support government restraints if the industry did not curb advertising aimed at underage audiences.
