They are everywhere. That one corner of an intersection where no store succeeds, while the other three corners thrive. In Chicago, I think of that haunted house at Halsted & Belmont. It was a clothing store, a hair salon, thrift store. No one could make anything stick. There are similar places I see here. A print shop closed and an upscale men's clothing boutique opened up, but doesn't seem to be faring too well. Retail is tough.
The places that buck the trend fall into a few categories: wildly popular brands (Starbucks), high margin variety (budget mobile phone sellers), and shops that go to great lengths to erase the smell of failure from the minds of local consumers. Major exterior renovations, extra press, events, and promotions, hitting the pavement to generate word of mouth. More than anything, pedestrians need to see signs of life. Going from a copy/printer shop which had zero foot traffic to an understated clothing store (with men's clothes, no less) does not bode well.