Most Knight Ridder websites will no longer charge for classified ads for household items and other merchandise, in an effort to attract more traffic and spur online and offline sales, according to an AP report. The publisher dropped the online-classified fees on Friday in 22 of the 27 newspaper markets served by its websites. The giveaway does not apply to most other categories, including real estate, automotive and help wanted, and it will start charging for classifieds featuring pets.