What's secondary research (why is it important) And an example

Please make it a bit long (about 6 lines) ​

Cool beans is a locally owned coffee shop that competes with two large coffee chains, planeteuro and frothies. alicia, the owner, hired two students to count the number of customers that entered each of the coffee shops to estimate what percent of people who are interested in coffee are visiting each shop. after a week, the students found the following results: 589 visited cool beans, 839 visited planeteuro, and 1,290 visited frothies. the students were surprised that cool beans had 139 visits on monday which represented 59% of all people who visited one of the three coffee shops on mondays. how many people visited one of the three coffee shops during the week?