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1. Pay-per-Use: A fee is charged for each time the font is used - whenever a web page with the font embedded is accessed, for instance - or for a specific number of uses.
This field's value could be a number (if licensed or a specific number of uses) or can be unlimited.
2. Pay-per-Download: A fee is charged each time the font is downloaded or for a specific number of downloads.
This field's value could be a number or be unlimited.
3. Pay-per-Time: A fee is charged per unit time that the font is being used. It could be per minute for a MMORPG, for instance, or per year for use in a time-limited ad campaign.
This field's value needs to be a number and unit of time. All licenses are assumed to be indefinite unless limited by this field or the Duration field in the Font Personalization section.
4. Pay-per-view: A fee is charged per viewer impression. This might be used for licenses where the utility/value-added of the font is greater due to higher visibility, such as billboards or banner ads. Or it might be used where the utility of the font increases due to increasing readership, as in newspapers or magazines.
