Fred Wilson writes:
Contextual advertising is when the ads are targeted against specific content.
Behavioral advertising is when the ads are targeted against a specific person who has exhibited a certain behavior.
Contextual advertising is content-based advertising.
Behavioral advertising is people-based advertising.
They are both effective and I believe they result in more relevant advertising which benefits the consumer.
I also believe that we are just seeing the beginning of how powerful these targeting techniques can be.