For many people, Tumblr is just a fun, blogging platform they use to express themselves and interact with friends. What many people don't know is that money can be made from using Tumblr. Tumblr is a lot different than other social media sites, as well as websites created to earn the owner money. In fact, if you use it correctly, Tumblr can be the perfect mixture of both those things. Because of the reblogging feature, any post you make could go viral. This is great, especially if you find the right post and have a lot of followers. There are many ways to monetize your Tumblr blog, including ads, paid URL shortening services, and many other ways. Obviously if you want to make money you need to have a lot of followers. How do you get a lot of followers? Be active on Tumblr! If you follow other people, reblog their posts, and like their posts, they often do the same for you. If you do this for awhile, you can build up a nice follower base and have the potential to make some great money off your Tumblr blog. Also, you need to pick a good niche for your Tumblr- what it will be about. Pick something that you like, but a lot of other people like as well. Some good possibilites are soccer, dancing, art, cats, etc. There's plenty of options- don't stress yourself out about picking the right thing. If you're knowledgable about the topic and enjoy it, and other people enjoy it too, then it is a perfect niche.
So what can you use to earn money with Tumblr. There are tons of options for this, some better than others. You can use Google AdSense, AdBrite, or JuicyAds to put advertisements on your page and earn money off of that. Another possibility would be creating a post about a really cool product on Amazon in your niche and linking to it using your Amazon Affiliates account. If you do this you earn a percentage of each sale, even if the person doesn't buy the product you posted. Paid URL shorteners also earn you money, but they're perceived as a bit spammy, so use them at your own risk. You could also use the clickthrough link option on picture or video posts to direct the clickthroughs to your site with ads, a product for sale, etc. There are literally hundreds of options. Use your imagination and be creative and you'll find the right one!
If you want to learn how to build up your Tumblr blog, or want more information about monetization, check out this site. It has great information.