I have a Tumblr, and have had one since before the site really blew up. But since then, I've had a strange relationship with it, and haven't ever truly understood its purpose. I first started using it for a little bit of everything. Mostly just re-posting art from my Deviantart though, and an occasional written entry. It didn't have much of a purpose as Livejournal was my primary blog and I have never been a big fan of reblogging.
It's nice to share things and all, but I find it kind of jarring how most people on Tumblr don't actually create their own content. They just go around parroting other people's like some kind of strange spambot at least 16 or so times a day. When I found this out, I unfollowed most of the people on my list. I didn't like my feed getting so clogged up that I could distinguish nothing but a long line of gifs. I also lost interest in Tumblr for years, because it just didn't seem like my kind of place to socialize.
I returned only a few months ago in a more permanent capacity, as I determined that I needed a place to basically splurge all of my thoughts and a whole lot of personal stuff. My Livejournal was outdated and nobody was really using that anymore, so I repurposed my Tumblr to do that. It is now mostly full of long-winded written entries that cover a lot of personal issues and thoughts, much like a more traditional diary, with some occasional bits of art and pictures.
Sadly though, Tumblr still isn't a great place for me to socialize. When people follow me, I can't tell if they're robots or actually people, because the communicating between others is kind of awkward. I'm still not sure how the responding and commenting works, but it seems very horrible and seems to operate on reblogging another person's post and typing a response in that. This is a blog website. Comments should be a priority. Yet it just seems like it isn't the type of place where people actually use words to talk about things substantially. I often feel like I'm posting things into a void, and like the few likes/reblogs/followers I receive are just from either robots or people who didn't actually read the content/thought the title sounded cool.
But that's okay. My Tumblr is mostly for myself anyway. And for my fiance to read my thoughts as well, because I communicate them much better to him when they are written. It's only public because it feels more purposeful to me to share my thoughts with others. Keeping it private makes the endeavor feel pointless.
I won't post a link to my Tumblr, because I honestly doubt that most people who would be on Tumblr would find it very interesting and might be made uncomfortable by a stranger divulging such personal things. If you are interested though, you can either ask me for a link or just Google it. It really isn't that hard to find.