One of the old "jokes" on social media - in discussion boards/forums/comments, anyway - is the person who pops in and writes 5 paragraphs in what had previously been a back and forth discussion amongst users. What's now called tl;dr (it's always nice to see some love for the semicolon in there) also used to be called "hey, get your own blog" - a way to tell people that they're hogging the conversation. And of course some people don't mean to - they don't realize that after two paragraphs that's how it appears to others, especially in the comment section. However! Now that we have blog posts in formats like tumblr with a dashboard of everyone's posts one after the other, even posts that are too long often make it seem like another tl;dr moment for some readers.
Tumblr and Booklikes both have a way for you to Not Be That Person. It's called, The Page Break. If you haven't noticed it yet it's because it's hiding at the end of your editing toolbar, quietly waiting for some love. Just to the left of the html icon.
Ignore the "for Printing" bit - this is all about how you present content to other people.
One way to use the page break - keeping reblogs under control. Often you'll have no idea whether you're the second person to reblog or the 2,002nd. The solution - a couple of sentences about why you're reblogging, a dotted line to show that's the end of your writing - and then only a paragraph of the reblog content before you add a page break. That way people see why you think the content is important (or why it made you laugh or whatever) and don't have to scroll past the same reblog they've already seen.
It's also a great idea to use page break in any review or post that you'll be sharing a lot of jpgs/gifs on, simply because if people are reading on a mobile device sometimes the last thing they want to do is wait til the images load.
Anyhow, just a thought. I sort of think about this sort of thing along the lines of "I don't vacuum after 8pm because: neighbors" apartment-etiquette that some people notice more than others. (Because vacuuming after 11pm is way into WTH territory - with 8pm you're usually safe. Non-apartment-dwellers don't usually think this way.) (Also a big no to my subconscious, I see what you're doing there, no, I refuse to vacuum now, even though the place needs it, stop that!) (Also I'm now wondering if this post could have used a page break. Hmmm.)
Added: Or if I'd been properly channeling the Expendable Mudge: this post!