Jakob Nielsen’s intelligent take on text-based (and contextual) advertising is called “Will Plain-Text Ads Continue to Rule?”

Jakob has always had (justifiably) unkind things to say about “traditional online advertising”, but he likes text ads, provided they are put in context by search results. I think that Jakob overly limits the effectiveness of contextual text ads because if the ads are truly placed in context, they also become a content point, just like other pages on the site the user is visiting. His argument regarding online classified ads being viewed as content not ads by online users is spot on — but it also applies to truly contextual text ads as well.