Oddly enough, not all blog owners yet understand the difference between "Jump Break", and other "Read More" features. And there are more than a couple "Read More" features available, in the Internet - some not so beneficial.
Occasionally, we see the confusion, in Blogger Help Forum: Something Is Broken.
I have 12 articles which must appear on my homepage. Just 10 of the 12 articles are showing up. When I added 2 new articles, another old post disappeared from my homepage.This blog owner, like many, suffers from the effects of auto pagination.
When I suggested using "Jump Break", to make the posts smaller, I was met with confusion.
Did you not look at the blog? I have "Read More" there, already.And looking at the blog again, I saw that he was correct.
Examining main page view, and a post in the the blog, I used my browsers HTML viewer.
HTML view shows a post which uses "Read More" - but not "Jump Break". Examining various blogs main page view, as HTML, we can see the difference between "Jump Break", and this "Read More" solution.
With "Jump Break", on the main page, one sees the post summary, followed by a link to the post page. The post page then contains the full post.
When clicked, the "Read More" code simply makes the entire post visible. This would be a clever way to display a post summary - if auto pagination was not involved.
Since auto pagination limits the number of posts based on total downloaded content, main page view, using "Read More", is limited by content which is not visible. This causes confusion.
With "Jump Break", each carefully sized post summary, in main page view, downloads only the post summary to the client computer. This makes each individual post relatively small - and allows the main page, even with auto pagination, to include a large number of posts.
Look at main page view for this blog. I display anywhere from 10 to 15 posts, at any time, in main page view. Long ago, you would see this post at the top of the page (but time has passed, and this post is archived). Do you see how small the posts are, as displayed on the main page?
With "Read More", however, even with the post displayed as a summary, the entire post is downloaded. Auto pagination then limits main page view to a handful of posts. Main page view looks smaller than it should - and the blog owner is left, scratching his head.
Only "Jump Break" works properly, with auto pagination. That is the bottom line. Don't settle for less than "Jump Break", if you want your blog, in main page view, to include a predictable number of posts.