Readers will make a judgement as to whether your full post is worth reading based upon how it starts, and they will continue reading if you succeed in connecting with them on one of a number of levels.
Opening links should pique interest and curiosity, highlight a need that your reader has to give them a reason to read more, show a benefit of reading on, and/or make some sort of promise to entertain, inform, teach, or offer something of value.
You don’t need to do all of these things in the opening sentence of each post you write—but if you want your readers to reach the bottom of your posts and to be persuaded by what you write, you’ll need to work hard early on at hooking them on some level.
Post Length—How Long Should a Blog Post Be?
The optimal length of a blog post has been hotly debated by bloggers for years, and there are a number of factors to consider when thinking about it, such as the following:
Reader attention span—It is pretty well documented that the typical web reader has a short attention span when it comes to reading content online. My own investigation into length of stay on blogs found that average blog readers stay 96 seconds. That’s a minute and a half to communicate to your readers. As a result many webmasters purposely keep their content length down to a level that is readable in short grabs.
SEO—There is a fairly strong opinion among those considered experts in search engine optimisation that both extremely short and extremely long web pages are not ranked as highly as pages that are of a reasonable length. Of course, no one really knows how many words are ideal in the eyes of Google and its fellow search engines— but the general opinion seems to be that a page of at least 250 words is probably a reasonable length. Similarly, many advise keeping pages less than 1,000 words.
Quantity of posts—One theory that goes around is that shorter posts allow you to write more posts and that more posts are better for generating readership with RSS and in search engines. Though I don’t know their strategy personally, some believe this is what sites like Engadget.com do with the high quantity of short posts that make up the majority of their content.
Topic/genre—The type of post that you’re writing will often determine its length. For example, when writing a review of a product, you’ll generally write a longer post than when you write a news related post where you link to something someone else has written.
Comprehensive coverage of the topic—Ultimately this has to be the main criterion that bloggers go with. Write enough to comprehensively cover your topic and then stop. Long posts for the sake of them are not a wise move—but neither are short ones that don’t cover the topic well.
My personal preference is to mix up my post length from post to post. I try to write one long post per day to give readers something meaty to chew on, but I also mix in short newsy posts most days.