I've been playing around with tumblr and I noticed you are way likelier to get reblogs/likes from posts that have good tags. I also noticed you can use the mass post editor to put tags on every post at once. My theory is that you can increase your tumblr traffic drastically by having a program that adds and deletes tags based on the current popular tags on tumblr. The tags don't need to be related to your post. If you're posts look interesting enough or catches someone's eye, they will click on it regardless of whether or not they think its relevant to their search. Now you could easily do this manually by changing a few tags everyday based on popular searches (they could just be tags based off of today's top google searches or twitter hastags). Any thoughts? I'd love for you guys to try it out and see if it helps your traffic. The key is to use a tag that's extremely popular, especially if it's really popular for only a few days because it's some sort of event or news headline.