Or, are you intending to convey that an admissions department's secure portal is a type which would preclude ad serving? [/quote]

This- the platforms and portals are very specific to this purpose (college admissions) and supplements need to fit the specified formatting, etc- most if not all the places my kids submitted used the same portal, or something similar enough to be easily used in the same way. There are specific formats for everything, from music to visual arts, etc. Though I imagine that social media might be viewed in certain circumstances, it’s not traditionally how arts supplements are submitted. But that’s the extent of my knowledge, and it’s already a few years out of date.