I absolutely agree with this article in the Guardian on how long load times drive away customers and create ill will. In fact, I gave up after about six seconds waiting for the linked site to open. I further agree with their assessment of moronic sites that require Flash for no good reason at all (which in itself sucks down the performance of a site):
Of course, speed isn’t the only thing that matters: it helps if your Web designer isn’t an idiot, like whoever created the Akamai Web site. This site requires users to have Flash installed in order to read a simple press release, which is the sort of thing the Web could well do without.