In a world where human knowledge doubles every 5-10 years, product managers fight to reduce their product/service complexity from an end user perspective. Lean experts will straightaway think about a product's internal complexity or externalising the complexity from the product. But I mainly refer here to the end user, who doesn't care about the development/production phase, but only his own experience. Since I read this communities dominates post in August, I understood that my Internet blogger's mind, was still in 2005 when the Internet was still something hype. Today 1.4 billion users have an email (400 000 corporate ones) and 4 billion have an active SMS account. Today, even if I was blind, I wouldn't be able to escape hearing the teens' phone buttons clicking all day long. Definitively, the user experience from a product interface and/or the user efficiency point of view, is not a static science. The design principles like the golden ratio seem to be anc...