From what I've heard (I know a couple of guys that work there), Tumblr is working on the spam and has made large amounts of progress.<p>I made a couple posts about this earlier this week. My site has nearly 15k Tumblr followers, so as a result, I see some of this stuff more acutely than most people.<p><a href="http://shortformblog.tumblr.com/post/11645079360/tumblr-likespam-problem" rel="nofollow">http://shortformblog.tumblr.com/post/11645079360/tumblr-like...</a> (on a couple of methods I've been seeing a lot)
<a href="http://shortformblog.tumblr.com/post/11654489531/tumblr-fake-profiles" rel="nofollow">http://shortformblog.tumblr.com/post/11654489531/tumblr-fake...</a> (on how the empty profiles have a payload)<p>I think a big part of the problem is that there's an easy-to-exploit black-hat SEO technique that many like spammers have been using. (To put it simply: You can be guaranteed that the phrase "liked this" shows up on most Tumblr pages.) Since I implemented the technique I mentioned in the first post — which I admit isn't entirely desirable, because it also blocks some relevant content too — my Tumblr spam has gone down significantly.<p>Also, note how, in that first post, I've gotten some spam notes in the past few days. It's because it contains the phrase "liked this" right in the post. I have the search analytics to prove it.