You might look for some company background information to understand the company mission and goals. In addition to searching the website you could look at Hoover's Company Profiles.
You might look for books in the library catalog about the company or its brand and marketing strategy.This branding/marketing information will indicate whom Nike is targeting and what their strategies are to reach their customers.
For articles, try Proquest Central and Academic Search Premier. You may want to search ABI Inform separately from Proquest Central as it has a lot trade and industry and market research content. Try a myriad of different combinations of keywords to find articles that are relevant to your search. look at the subject headings to see how articles you like are described. Look for articles that compare Nike's sales to other companies.