Smart business or a monopoly??

AMD filed an antitrust lawsuit against Intel last year. AMD alleges that Intel's size gives it an unfair advantage in the market and that giving perks to customers who buy more, and other Intel practices control the market. Intel says these are just smart business practices. So what do you think- is Intel really a monopoly or are they just doing smart business? And is AMD turning out to be real competition-they controlled twenty percent of the market at the time of this article?