An advertiser would be ready to pay any amount for an ad that a user never saw. Many brands are redefining how their ads are considered viewable.
Page view-ability rate
It is important to balance the page view-ability percentage with the ad served. Viewability rate is nothing but the percentage of ads viewed over the total number of ads served. The advertiser works with the publisher to configure for a higher view-ability rate.
AMP ad component uses data loading strategy to tweak pages for higher view-ability rate
Data Loading Strategy -AMP-ad
The float value of data loading strategy is between 0-3. The float value is the no. of viewports between the user and ad page. A publisher who wants to increase his view-ability percentage has to keep the float value as small as possible. The larger the float value, the lesser the runtime will wait for ad request and vice versa. If a publisher does not configure the float value then the runtime default value is 1.25. This is tested and tried value that delivers high view-ability. There is no drastic impact on total ads through this float value.
Render on Idle Effect
In Render on Idle, the runtime requests ads deep down the viewport if all other page components loading is done and were idle. This may result in view-ability rate drop but could increase ads served. It may improve the possibility of loading in time for the users. It is to be noted that when data load strategy gets configured, render on idle gets disabled.
The industry is moving to compensate view-ability and views. It has become easy for Publishers to configure and test different ad loading strategies. They just need to change a single code line on an AMP page. Even they can consider additional flexibility through CMS configuration.