This is answer is subjective and will most likely vary from one person to another. Depending on the place of work and/or reasoning for exploitation are important variables to be considered. For example; is the person willingly subjecting to being exploited? And even if they are, does it make it right? So my final answer is... there is not enough information given to decide this. If anything, I think every single point should be considered when deciding if they should or shouldn't be used as Billboards. In this context, do you mean employees wearing the brand/store they are working for, or employees being expected to constantly be in one's line view promoting their product?
