Marco Arment quipped on Twitter that web designers need to take HiDPI displays seriously, and adapt their designs to look great on them.

If you’re a web designer, you really, really need to get a Retina MacBook Pro so you can see how bad your site looks on it and fix it.

— Marco Arment (@marcoarment) July 5, 2012

The short-sighted reactions he received revolve mostly around simple mathematical analysis: because HiDPI displays represent a relatively tiny percentage of all users, it is not worth a designer’s time to cater to that niche group.

I confess that after the iPad 3 was released, I paid little attention to adapting my site to support HiDPI. But when Apple announced the Retina MacBook Pro at WWDC, revamping all of my apps and my web site jumped to the top of my list of priorities. My apps are shaping up nicely. My site? Let’s just say it’s still on the top of my list.

Why? Because HiDPI customers may be a fringe group, but they are a forward-facing fringe. They represent the users of the future, and the more we cater to them now, the more deeply embedded our products and designs will be in their culture. The future culture. The same arguments apply to aggressively embracing newer web browsers standards, and the latest technologies in platform operating systems such as iOS and Mac OS X.

It doesn’t hurt that the forward fringe tends to be rich and influential, compared to other niche audiences. When some backward-compatibility quack notices that your site renders poorly on IE5, they may scream it from the rooftops, but it won’t make a serious dent in your sales or reputation.

In contrast, when a Retina early-adopter discovers how beautiful your site and software look on their fancy computer, they’ll be that much more likely to open their wallet again. When John Gruber or Jason Kottke happens upon your beautifully designed, HiDPI site, he’ll be that much more likely to spread the news about your forward-thinking design to their friends and readers.

Target the forward fringe.