Isn't it funny how high gas prices can hurt one retailer but don't seem to bother another? While Rent-A-Center (NASDAQ:RCII) has spent the past few years blaming external factors for sliding same-store sales, Aaron Rents (NYSE:RNT) simply delivers the growth.

Second-quarter results were certainly worth owning. Excluding certain non-operating items, revenue climbed 20% and earnings grew 31%. Rentals and fees were up 21%, and franchise royalties and fees were up 27%. Underpinning all of this, same-store sales were up 7.3% in the quarter.

As Aaron Rents management said, the numbers speak for themselves. Aaron Rents has worked hard to make its stores stand apart -- they're brightly lit, they're large, and they look like regular retail stores for housewares and electronics. Simply put, you don't feel dingy or shabby walking into one. Don't believe me? Look at the numbers -- obviously, a whole bunch of somebodies agree with me that Aaron's is an appealing place to patronize.

I think Aaron Rents works hard to keep customers coming through the door. Although a lower cost of ownership for customers means lower margins in the short run, it means more business in the long run. Ditto for keeping fresh and desirable merchandise in stock. Last but not least, a quick look at the 10-K doesn't turn up any class action lawsuits. Bottom line -- targeting good customers and keeping them happy is a winning approach.

Excellent results notwithstanding, investors should continue to keep an eye on the same-store-sales trend. Growth has been decelerating a bit, but it's also fair to point out that you can't maintain double-digit same-store-sales growth rates indefinitely (well, unless you're Chico's). I would suggest that in raising guidance, management is expressing its confidence in the same-store-sales trend, but investors would always do well to keep a skeptical eye on even their best-performing stocks.

If you're passing by Rent-A-Center, offer the store a ham sandwich, because it looks as if Aaron Rents has been eating Rent-A-Center's lunch lately. Despite a high trailing P/E, the shares don't look terribly overpriced. Management is guiding toward solid mid-teens growth, and the company continues to produce solid internal rates of return. Assuming that Aaron Rents customers don't suddenly start using this other gasoline that has apparently been hurting the other retailers, things should be fine for the near term.

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Fool contributor Stephen Simpson has no financial interest in any stocks mentioned (that means he's neither long nor short the shares).