Quantitative data are those data that can be put in numerical form. They would include things like sales data but would not include things like emotional responses to the make-up.
Quantitative can be used in many ways in this research. You can look at sales numbers to determine which kinds of products sell the most. These would be your “must have” products. You could also use sales data to determine if artists and regular consumers are buying different things as their “must haves.” You might look at how responsive both groups are to changes in price.
Quantitative data could also tell you things about the competition. You could, assuming you could find the data, look at what other brands of cosmetics your target market is buying. Finally, quantitative data could help you with your marketing. You could survey customers, looking at whether they are aware of your marketing campaigns. If they are, you can try to find out which publications or other sorts of media they are seeing your ads in. These would be quantitative data because you could numerically record how many people encountered your marketing in which places.
In all these ways, quantitative data could be used to study cosmetics marketing.