The announcement earlier this week that bookstore giant Barnes & Noble is for sale is important to city planners for two reasons.

First, however the deal comes together, the sale will almost certainly result in the closure of some of Barnes & Nobles' 720 U.S. stores. Closures could begin even before there is a sale, as the company tries to increase its appeal by shedding its weakest outlets.

Second, and more importantly, the troubles that Barnes & Nobles is experience provide another example of the changing nature of retail sales, and one more warning about basing land use plans or developments on specific uses or businesses. How Americans buy things, and even what we buy, is evolving almost as fast as planners can process development applications.

When I was in downtown Seattle last week, I came across an honest-to-goodness newsstand. Tall racks located right next to the sidewalk offered hundreds of mainstream and esoteric magazines, local and out-of-town newspapers, racing forms, puzzle books and even a few paperbacks. It was exactly the sort of operation that used to attract crowds in any large or mid-sized downtown. But the newsstand I saw in Seattle struck me as quaint, almost anachronistic.

Is the full-on bookstore going the way of the newsstand? Quite possibly. Independent bookstores have been shutting down rapidly since the 1990s, partly because of competition from the likes of Barnes & Noble, but mostly because reading – and buying – habits are changing.

You don't need me to tell you that people read things online all day long. You're doing it right now. And you don't need me to tell you that people buy things online all day long, too. Last year, Barnes & Nobles' biggest competitor, Borders, closed all its stores in the United Kingdom. Borders has barely staved off bankruptcy in this country. I'm not going to bury Barnes & Noble just yet – the business wires report the company has at least two serious suitors – but there's no denying the company is struggling.

With the big movement to electronic books, people are likely to buy even fewer printed books in the future. It's a story familiar to any recorded music retailer. Forrester Research analyst James McQuivey told the Los Angeles Times, "It's really starting to be clear that bookstores are, if nothing else, a very valuable way to promote e-readers and e-books."

As recently as five years ago, nearly every proponent of downtown redevelopment, a lifestyle center or a mixed-use development fought to get a bookstore. They couldn't contain their glee if they managed to snag a Barnes & Noble or Borders. But if the analyst quoted above is correct, the bookstore that was so prized only a few years back may continue to exist only as a marketing tool for sales consummated elsewhere.

I recognize that retail trends come and go. Heck, I'm old enough to have slurped a milkshake at a Woolworth's lunch counter. But retail trends used to hang around for a generation. Now a big trend might last seven years.

My point is this: Basing a specific plan, redevelopment plan, or development project on certain retail uses is a very dicey proposition. The bookstore that was a lynchpin 10 years ago may not exist after this Christmas shopping season. Who really knows how other segments of the retail market will evolve over the next few years, let alone over the next 20?

I probably sound like I'm advocating form-based zoning. Maybe so. What I'm really advocating, though, is a focus on making great places – the sort of places that remain vital even while uses evolve and adapt. When you're building and rebuilding a city, what matters are the bricks and mortar, the public plazas and landscaping, the circulation systems, the architecture – the stuff that will survive while numerous retail trends rise and fall. I think most people who have studied cities and city planning understand this fundamental concept. But I also think that people can get distracted by the latest shining object.

– Paul Shigley