Web sites for newspapers, magazines and television stations might be hungry to make money with digital advertising, but you wouldn’t know it by the way some of them do business online.

A new study released Monday by the Pew Research Center Project for Excellence in Journalism looked at 22 news Web sites and more than 5,300 digital ads. It found that many of the sites had not attracted the same advertisers online as they did on other platforms.

In part, these sites were failing to attract online ads because they were not using technology that would customize ads based on their users’ online behavior. For example, a user searching for tickets to a Broadway show might see ads for that show.

The study, which looked at Web sites for 11 newspapers, four magazines and six television outlets, as well as two online-only sites, focused on premium digital ad placements on home pages or at the top of article pages, which have generally cost more to buy.