My take on “Web design in a Retina world”

I read an interesting article on Johan Ronse’s blog about how to design (or is it “develop”?) for a Retina world (Retina being Apple’s marketing speak for high pixel density screens, but you guys knew that). I’ll be honest, I’ve not followed up on all the Retina-buzz, if only because this performance-nut isn’t particularly happy about the sudden need for higher quality images being shoved down people’s data-throat (same with webfonts actually). Because, after all, 14Mb really isn’t “nothing” Johan, given the average webpage is around 1.1Mb.
What seems to be missing in the few articles I did read up until now is this; why do we want to deliver high resolution images to high pixel density screens to users on a broadband connection (assuming we can keep others safe from these high fidelity images, but that is doable)? Because it looks better? Maybe, but what purpose does that serve? What purpose does your site serve? Do you want people to stick around and return, reading your stuff for a long as possible? Or are you in the ad displaying business? Maybe you sell products or services? The question is; how are Retina-ready images going to impact your KPI’s?
Let’s assume those nice crisp images will have a positive impact on your site’s usage and/or ad views and/or sales and let’s also assume (although it is a proven fact rather than an assumption) that the longer download time will have a negative effect on your business. Given these two assumptions; which one will have the biggest impact? My hunch would be the negative impact of longer download time, but I’m biased. The answer to that question really depends on your KPI’s, on your business and on the technical implementation.
The only sound advice anyone could give: do multi-variate testing, compare your KPI’s for your site with and without Retina. Going Retina might help your business, it might harm it. I for one am not switching to Retina any time soon, I don’t see the need for it from the safety of my ivory performance-tower. I’m biased, you know.