The main reasons PayScale and Salary.com give such different salary estimates include: Data sources - PayScale uses crowdsourced survey data direct from employees, while Salary.com relies more on proprietary surveys and predictive modeling. Customization - PayScale offers highly tailored reports based on your niche experience. Salary.com focuses more on generalized job profiles. Target users - PayScale caters to individuals looking for granular salary insights. Salary.com serves larger enterprise compensation needs.