Starbucks (NASDAQ:SBUX) continued to show its appeal with caffeine fiends, reporting impressive same-store sales yesterday evening. As summer draws near, the backdrop is set for some important aspects to watch.

The coffee purveyor said that May's same-store sales rose 11% from the same time frame last year, while revenues increased a healthy 27% to $404 million. Same-store sales were the same when compared to last month's, with a slight decrease in revenue gains, which last month rose 29%.

Starbucks continues to exceed its conservative guidance for how much same-store sales can continue to grow. However, one has to wonder how certain initiatives are going to work. Last quarter, the company announced its introduction of some non-coffee, summer-friendly iced drinks, in an obvious bid to lure people who don't drink coffee, as well as provide a kid-friendly beverage.

On the competitive front, some people wonder if there's trouble brewing. On our Starbucks discussion board, people have been kicking around rival forces' chances, including Wal-Mart's (NYSE:WMT) new in-store coffeehouse, Kick's Coffee Cafe. There's also some concern about Allied Domecq's (NYSE:AED) Dunkin' Donuts and Motley Fool Stock Advisor stock Krispy Kreme (NYSE:KKD), both of which are testing in-store outlets in a few Wal-Marts, as well as what may be a high-end contender, Peets Coffee & Tea (NASDAQ:PEET).

For now, we've got a view of a month where the early hours of summer haven't daunted the Starbucks set. Though the specter of rising costs for dairy products -- and any possible price hikes -- still lingers, the numbers show Starbucks keeps a firm grip on many people's coffee breaks.

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Alyce Lomax does not own shares of any of the companies mentioned. And no, she doesn't want her latte iced.