A Bloglines question

I read blogs through Bloglines. For most of my 108 (!!) feeds, the full content of new posts shows up in Bloglines. I will often go onto to the actual blog--to comment, to see pictures, etc. If I am quickly looking through new posts in the morning before class or during a break, I will click "keep new" on a post to indicate that I want to go over later to comment or read more or whatever.

So my question. A few of you show up in Bloglines as having a new post, but only the title or the title and a few lines of the post is visible through Bloglines. Do you do this on purpose? Is there some kind of option that allows only a certain truncated amount of text to show up in readers like these? If so, why? Is it a statistics counting thing? Do you want to know how many people are actually reading your blog, since a reader reading only through Bloglines doesn't show up? Or is a feed type or blog type issue?

For whatever reason, I will rarely rarely take the time to click over and check out a blog post that only has a title or a few lines of text showing. It seriously has to say something like, "The world is on fire, and Christian Louboutins are on sale for 90% off at . . ." to get me to go the actual blog. This is weird because I will and do go to actual blogs through Bloglines, but only when I can read or skim the whole post on Bloglines first.