Adblock Plus is the most popular ad blocker available for Firefox, Chrome, Opera, Safari, Android, and Internet Explorer – costing websites millions in revenue each month.
While most online ads are blocked by the service, they also have an Acceptable Ads policy, where some ads are displayed.
Adblock Plus explained that when websites apply to be on the whitelist, the ads they want to whitelist must meet the Acceptable Ads criteria.
“After applying to be whitelisted and agreeing to meet criteria, a small percentage compensate us while the rest are free,” said Adblock Plus.
The company said that only advertisers that stand to gain more than 10 million incremental ad impressions per month because of whitelisting are asked to pay a whitelisting fee.
How the whitelisting fee is calculated
Adblock Plus said it calculates the licensing fee as a percentage of the extra revenue the advertiser earns after whitelisting.
“It is not based on total ad revenue, but rather the value our service creates.”
This revenue allows for more employees to be hired. “Software engineers have to maintain the whitelist,” it said.
Adblock Plus said Acceptable Ads provides value to publishers that was previously unavailable, and encourages better ads.