McDonald's (NYSE: MCD) announced that global same-store sales rose 8.1% in August. With 36,000 stores worldwide and annual sales of well over $21 billion, the growth rate is extraordinary. The company's shares are up 2% in premarket trading and the stock could easily break its 52-week high of $53.22.

A food retailer this large growing this fast is likely to be eating someone else's lunch. Shares in Yum Brands (NYSE: YUM) and Starbucks (NASDAQ: SBUX) have lagged McDonald's so Wall Street may suspect that their same-store sales will not be as robust.

McDonald's has been clever, and it seems odd that other food and coffee retailers have not matched some of its moves. Many of its stores are open 24-hours. Almost all in the U.S. open at 5 a.m. to catch the early breakfast crowd. The majority of Starbucks open at 6 a.m.

Investors know that there is only so much air in any room. If McDonald's can keep increasing its sales at a rate faster than the competition, it is likely taking share and cutting into revenues at other companies.

There is no way for the likes of Starbucks to shake this perception without showing that its same-store sales can move up close to 10%.

Douglas A. McIntyre is a partner at 24/7 Wall St.