As for the Ajax-style approach, it's my understanding in that case you are having every user load all the data on the page, but just not showing some of it, but a goal here is to be able to present more stories in less space and keep the page size managable.
My thoughts on the continuation approach is that it's fine unless you break up long lists in the middle. I like to scan the sales and the reviews, but I'd probably never click the "continued" link if you broke the list in half. Breaking it like you did today with the previous day's sales is fine, though. If you want to shrink the page, maybe consider a 2-column layout for the lists that are only a few words per line.
Keep up the good work. Been reading since, oh 1997? (and no adblock)