When Wikipedia revealed its massive website redesign last week, not everyone was thrilled. One reader called the new columns "ludicrously narrow," while another said an image surrounded by white space was "a really bad idea." The larger font and pictures looked nice, but Wikipedia's users liked the old site design, thank you very much--the one that hasn't changed much since the site launched in 2001. 

Craigslist is another example of a site that refuses to update its look and feel. It relies on email to correspond with users, even in the era of SMS and social networks, and has rarely, if ever, changed its text-heavy design. You can add Drudge Report and Amazon to the same list. These sites might be ignoring design innovation but they seem to be doing just fine. 

"The desire to redesign or change often comes from the internal people wanting to mix it up or remind people they're out there," says designer Shane Mielke, who's worked on campaigns for Mazda and Call of Duty. "Sometimes change happens because there's turnover and the new director wants to put her personal stamp on something." But it isn't what customers want. 

It's true that customers appreciate crisp, clean design. But if it's confusing--or doesn't work--high design isn't enough to keep them coming back. Here's what really matters when it comes to Web design. 

Users Love It

It's hard to believe anyone can appreciate Craigslist's '90s aesthetic, but surprisingly, most users do. "Sites like that are very personal to people," says Mielke, noting how Facebook infuriates users whenever it tweaks its News Feed. "Facebook is integrated into their lives. They don't want their News Feed to be all the popular posts. They want the latest news. Any time you mess with something like that, you're going to hear about it." 

It Simply Works 

Looks aren't everything. Great design on the Web is about a great user experience and a layout that makes sense, says Mielke. If something is working, why change it? "If you're geared toward purchasing, make that flow clear," he says. "If it's marketing, you want to make it as close to possible as you giving a personal presentation to someone." Refreshing for refreshing's sake simply won't work. "A lot of people sort of assume that they need to innovate to maintain freshness and relevance in a marketplace," adds Matt Chmiel, senior content strategist at Code and Theory, a creative agency in New York. "But it's really about what you're communicating to your customer." 

It's Flexible 

Another thing that trumps high-concept Web designs? Flexibility. "Everything [on sites these days] is being treated in a modular way," says Chmiel, who helped redesign the Los Angeles Times' site, which, for the record, doesn't fall into the category of ugly websites. "You see more fluid design and more adaptable presentation of content. The Times has "basically a flexible system [that allows] the homepage--or business landing page--to look different at any given day or time." So if you want to tell a big story, you can, but every story won't look the same. Rather than stuffing content into a template, the backend allows the story to be as short or as long as it needs. 

It Reflects Your Brand 

YouTube is synonymous with videos, and on the surface its homepage hasn't changed. But execs are always looking for ways to grow the site's audience. Knowing YouTube draws 1 billion users a month, Nundu Janakiram, a product manager at YouTube who oversees the homepage, didn't want to do anything dramatic that might turn them off. "We've explored rethinking the [video player's] buttons, but when you show them to users, they're like, What is this? Why did you change this? It doesn't feel like YouTube anymore." To maintain familiarity, he improved the player from the backend so it would play sooner, with sharper clips. "It's about finding that balance between what's familiar and a comfortable user interface," he says.