Twitter and Tumblr used to be spoken in the same breath as Facebook, moreso Twitter than Tumblr. Now, it seems Twitter is dying a slow, creeping death. John A De Goes did an in-depth analysis and proposes Twitter 2.0. Personally, I haven’t had much of a negative experience with Twitter, but others certainly have (see Leslie Jones). In fact, the smartest thing I’ve done is turn off retweets. I expect micro-blogging will still exist in the future, but maybe on some new social media incarnation.
As for Tumblr, I used to use the service as a type of commonplace book. It was easy to add pictures, quotes, videos and the like to a Tumblr blog, but ultimately it was a time suck and interfering with my own creative output. When Yahoo purchased Tumblr, I shrugged. Now that Tumblr was bought out by Verizon in their deal for Yahoo, I would guess the service won’t be long for the interwebz. CJ Chilvers makes an excellent point about the future of Tumblr and makes the case for Medium’s future demise as well.
Ultimately, its important to simply own your own platform.