Analysis: Weekly Web Watch - Why the online marketers need to confess their love of 'cookies'

The companies that serve online advertising have over the past year started to take the profiling and targeting of Internet users to a new level. Ad networks, such as DoubleClick and 24/7, along with other media planning firms which serve ads, can now tell as soon as someone arrives on a site where it delivers ads, whether that person has visited one of their clients' sites in the recent past, and even which pages the person visited.