Is it necessary to ascertain the nature of the use of cosmetic products (for adornment or not) to ensure the lawfulness of money earned from marketing for an online cosmetics company?

The basic principle regarding sales is permissibility and lawfulness, unless the seller knows or strongly believes that the buyer will use the item for something unlawful, in which case the sale becomes prohibited. As for the online marketer, they do not deal directly with buyers, and their work is limited to advertising the product. Therefore, there is no blame upon them for marketing items that are permissible in principle, even if these items might be used for unlawful purposes. The responsibility then falls upon whoever uses them in an unlawful way. Consequently, there is no harm in working in the marketing of permissible cosmetic tools and supplies.