Usage describes where the work can live
A photoshoot creates assets, but a commercial booking also needs clarity about how those assets will be used. Website use, organic social media, paid advertising, retailer displays, outdoor advertising, print and broadcast are different kinds of exposure.
The broader the campaign, the more important it becomes to state the channels explicitly instead of relying on a phrase like marketing use.
Duration and territory matter
A campaign that runs for three months in one market is different from an open-ended campaign distributed across multiple countries. Usage terms commonly identify a time period and territory so both the brand and model know the boundaries of the agreement.
If a successful campaign needs to continue, renewal can be discussed instead of assuming the original agreement lasts forever.
Put the commercial reality in writing
Usage should reflect the actual media plan. If paid social, ecommerce, in-store screens and billboards are all likely, say so before the shoot. Clear scope makes pricing more accurate and reduces friction later.
This is not merely administrative detail. A model's face can become strongly associated with a product, so usage and exclusivity are part of the commercial value being purchased.