Page Size – How Big is Too Big?

Keith and I were having a discussion today about what should be the upper size limit for home pages. This has carried on into an interesting thread at Asterisk.
I tend to fall into the camp of supporting the lowest common denominator, the dial-up user.

Although Keith was of the view that not so many people in the US (our target market) are still using dial-up, a quick review of some stats shows that broadband penetration is currently at around 21%, and is expected to reach 50% in 2008. Looks like we’ll need to cater for the humble dial-up user for some years to come then.
I tend to rely on the experts to guide me and so read Andy King’s articles regularly. Although Keith calls him the “speed nazi”, I think there is a good middle ground to be found between going for page load time and providing your visitor with a decent experience once they get there.
So, in answer to the question “How big is too big?” my personal response is that 50-80KB is a good target, and anything over 100KB is too big. What’s interesting is how many major web sites completely blow through this ceiling, sporting page sizes of 150KB+.
I don’t know what kind of user-testing they’ve done, but I have to feel they are not providing a good initial experience for their dial-up visitors. I know I’ve had trouble with page load times on some e-commerce sites, and I’m on broadband.