Website Response Times An Article by Jakob Nielsen www.nngroup.com Users really care about speed in interaction design...A snappy user experience beats a glamorous one, for the simple reason that people engage more with a site when they can move freely and focus on the content instead of on their endless wait. 0.1 seconds gives the feeling of instantaneous response. This level of responsiveness is essential to support the feeling of direct manipulation. 1 second keeps the user's flow of thought seamless. 10 seconds keeps the user's attention. A 10-second delay will often make users leave a site immediately. uxperformanceinteraction
Never enough time Time pressure is probably the foremost reason behind the emergence of bulky software. The time pressure that designers endure discourages careful planning. It also discourages improving acceptable solutions; instead, it encourages quickly conceived software additions and corrections. Time pressure gradually corrupts an engineer's standard of quality and perfection. It has a detrimental effect on people as well as products. Niklaus Wirth, A Plea for Lean Software Deadlines are bullshitThe Thing-deadline calculus