The goal of quantitative research is to evaluate the data, and the usability of an existing product, compare a product with competitors and compute ROI. It helps to answer questions: how many and how much? The advantage of quantitative research is a possibility to have a big picture view of the product. The outcome is a report with hard data and the most important patterns of the users' behavior of the product.
Based on many users - which show the most common paths without the pains and obstacles which discouraged them from ending the process - the quality of data depends on a number of users.