Readers best remember sponsorship ads placed in the middle of online newspaper stories, but those ads also annoy them the most, reports BtoB Online, citing a study by University of Missouri-Columbia School of Journalism professors aiming to find out whether the location of a sponsorship ad in would confuse readers or hurt the e-newspaper's credibility.

Although the publication's credibility seems to remain intact, the upshot seems to be that the sponsor gets blamed for interrupting editorial flow with the sponsorship ad - or readers initially confuse the ad with content and are then annoyed at the apparent deception.

Attitudes toward sponsors that placed ads at the end of a story were the most positive, according to the study.