The problem for publishers is likely to get worse as more and more companies, such as Samsung and Three, announce plans to let users block online advertisements.
"Several companies have jumped on the ad-blocking bandwagon," said Daniel Knapp, director of analysis at IHS Technology, to CNBC in an email.
"Ad blocking is an expression of massive consumer dissatisfaction with the way the ad industry works."
One alternative to funding content besides ads would be a system of micropayments, where users pay a small fee for each page they view, according to David Schatsky, senior manager of emerging technology and business trends at Deloitte.
"You could have an option to not view advertising and instead pay a couple of pennies per page as you go," he told CNBC in a phone interview.
He explained that micropayments - facilitated by bitcoin – could be given to a publisher for the time a user spends on their site.