Sure online ads may be annoying. When they eat as much as 79% of your mobile data plan they can get seriously expensive. 

A hit to the consumer pocketbook is a score for an ad blocker. In either case, both are worrisome to publishers who need ad revenues to feed the news kitty to retain viewers. Reducing page-load times has attracted recent innovation (Google Accelerated Mobile Pages and Facebook Instant Articles). Now under study are the chunks of mobile data used by ads.       

Laura O’Reilly of Insider Business writes that a new report from Enders Analysis found that ad content accounted for between 18% to 79% of mobile data transferred, depending on the site. Enders, a subscription research service covering the media, entertainment and mobile, studied a number of popular publishers in a small-scale experiment. 

“The researchers concluded that it is reasonable to say advertising accounts for half of all the data used by publisher pages loaded over mobile data networks on the iPhone 6,“ O’Reilly writes. "Publisher mobile pages are bloated and advertising is an enormous part of that," she quotes Enders as saying in the study.  Ads also can increase page load times.