I admit I'm on an "old" system: Mac OS 10.4.11
Last year I found amazon.com so slow as to be unbearable. Every time I visited the site, I would have to reload the page at least once to get the whole page to appear, usually twice, and often reloading three times. After that, I gave up. Given that I spend a lot of time on Amazon, this ate away at my time. It seems to have gotten worse the past couple years.
So I switched from Safari 4.1.3 to Firefox 3.6.18, which is the last version of Firefox that will work on my system. It was an improvement, but only a little. Rarely will Amazon pages load on the first try. Average twice, three times reload, then I give up. The Wish List really bogs things down, though once you get the page loaded you can change to "compact view."
So I've tried the following browsers:
Safari 4.1.3 with Pith Helmet ad blocking
Firefox 3.6.18 with AdBlock Plus
Chrome is not an option. Upgrading my system is not an option.
For the past few years I have noticed my browser(s) choking on sites that did not seem to be so much trouble before, sites like Forbes, Washington Post, Wall Street Journal, YouTube, airline sites, National Review, Ranker, and AT&T (my service provider, of course).
I assume the usual culprits:
1) "Old" operating system.
2) "Old" or "wrong" browser.
3) Using a Mac/Mac versions of browsers, which many web sites don't like.
5) Sites that are heavy on ads and animation (but I can usually block these).
6) Sites that get heavy traffic.
7) Sites with poorly written code.
Of some interest, though I imagine you know this:http://www.fastcompany.com/1825005/how-one-second-could-cost-amazon-16-billion-saleshttp://www.webinsation.com/what-makes-a-website-load-slow/