I've been having this discussion with a co-worker of mine for the past 3 years. It's doesn't make how well designed or feature rich your website is. If it's slow, then you have failed. Performance is not a nice to have. It is everything. Another interesting point in the video, is that non-tech savvy user have even less patience for slowness. You would think it would be the opposite, but I can attest to this after watch my dad use a computer.