Another quarter, another dreary result for dining chain Ruby Tuesday (NYSE:RI).

Same-store sales dropped 8.9% at company-owned restaurants (franchised sites did even worse), though total revenue did tick up 7.2%. Margins softened pretty much across the board, and net income dropped by about 16%.

Ruby Tuesday's slide is nothing new, and while management seemed enthusiastic about its chances of reversing course, future guidance wasn't especially uplifting.

I believe that Ruby Tuesday's woes have a simple explanation: what I call the TipsyMcStagger's issue. Simply put, if you removed all appearances of the restaurant's name, how many customers could readily distinguish Ruby Tuesday from Applebee's (NASDAQ:APPB), O'Charley's (NASDAQ:CHUX), Brinker's (NYSE:EAT) Chili's, or TGI Friday's?

The problem may be easy to spot, but it's considerably more difficult to fix. I have a hunch that the solution revolves around distinct and desirable food. Red Robin (NASDAQ:RRGB) focuses largely on good burgers. Cheesecake Factory (NASDAQ:CAKE) offers good food in huge quantities. P.F. Chang's (NASDAQ:PFCB) has its distinct Asian menu. All have enjoyed recent success.

To that end, I'm not sure that Ruby Tuesday's accelerating commitment to advertising is the right answer. The company is right to get the word out about its revised, burger-focused menu. But if that menu isn't distinct and appealing enough, all the advertising in the world won't build a sustainable niche in the brutally competitive restaurant trade.

Now for the good news. Margins remain solid, and the company's return on equity surpasses more than a few of its close competitors (and the industry in general). What's more, Ruby Tuesday has numerous restaurants already in place across the country. If management can build a distinct menu and dining experience, the business could enjoy a lot of positive leverage.

For now, though, I'd rather nibble on appetizers at the bar than sit down at a table with this stock. Good investment ideas often include distinct and defensible competitive advantages. I just don't see yet how Ruby Tuesday has distinguished itself from all the other buzzing neon bar-and-grills.

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Fool contributor Stephen Simpson has no financial interest in any stocks mentioned.