Microblogging Wars Escalate: Posterous Claims Tumblr Blocks Its Autopost Feature

Posterous users can automatically push content posted to their blogs onto other platforms, such as Facebook, Twitter, LinkedIn, Flickr and so on. Up until recently, people could even post content like text, pictures and videos to their Posterous account and subsequently have it auto-posted to a Tumblr blog.

Now, as of this morning it seems, people who try to link a Tumblr blog to the Posterous service in the latter’s back-end get served the following notice, which leaves little to the imagination (emphasis ours):

Link Your Tumblr Account

Your full blog post will get autoposted to your Tumblr. Don’t worry about where you’re going to host your images, files, or music anymore. We’ll always just do the right thing.

Tumblr autopost has been temporarily disabled — seems like they are blocking our API requests at present moment. We’re working on getting this resolved. In the meantime, you might try emailing Tumblr support about it.

In other words, Posterous says Tumblr no longer wishes to host content automatically pushed from Posterous to them, and has thus technically disabled users from autoposting their content. And Posterous is telling users it is investigating the issue and “working on getting this resolved” which means they’re either talking to Tumblr or hacking a workaround.

It’s always possible Tumblr isn’t intentionally blocking API requests from Posterous and that there’s a technical issue that Tumblr will resolve. It also appears Tumblr has opted not to block Posterous’ import tool, which enables people to make the switch to the latter easier.

Update: and indeed, Tumblr CEO David Karp tells me that Posterous hasn’t been blacklisted at all, and that it’s probably just a case of them hitting Tumblr’s normal API throttling, which he adds recently became more aggressive in cases where clients make repeat requests with bad login credentials.

Karp also points out that they’re happy to help sort this out and currently looking into it.

Either way, there’s clearly been a feud growing between the two companies, both backed by venture capital firms, as of late. Both operate in the same, effortless-blogging platform space, and Tumblr is the bigger one and growing faster, but it has also been around for longer and definitely feeling the Posterous heat.

Last June, Posterous embarked on an aggressive switching campaign to attract more users, and one of the companies they singled out was of course Tumblr. Their message back then:

Tumblr is a pretty cool service. They offer easy set up, loads of funky themes and super-simple reblogging. But blogging on Tumblr is sort of like being in high school. But you know deep-down that you can’t be in high school forever. Eventually, you have to move on.

Unlike TwitPic, Tumblr at the time didn’t respond to the campaign by threatening legal action, nor did they block the Posterous auto-post feature as far as we know. It would have made more sense then than it does now, but here we are.

Posterous nor Tumblr has responded to a request for comment so far, but we’ll update if and when they do (update: see above for comment from Tumblr).