Based on Impressions

For every 100.000 digital impressions, InBrowser ordered the advertiser gets 7% of impressions for free. In this case, it means that she gets 7000 impressions for free. 

Non-Progressive

...

The unit count shows now that the customer has bought 240K impressions for total revenue of 13200 €. This earns him 7% * 240000 = 16800 impressions.

Progressive 

...

A progressive calculation would only allow full batched of 100000 AI and show a total of 14000 earned units. 

...