You don't get it until you have a go ha its a bit addictive really.

You have your blog. People make them for different reasons. I post things i like, be it a photo, a video, thoughts and feelings, or soppy pictures of me and my girl.

I also like how its a bit of a diary. You can go back in time and see how you felt at different times. You tag each post with key words. People do searches for key words and find your stuff. Then they might reblog on there tumblr your stuff because they like it. Theres loads of awesome stuff on there that you don't see anywhere else.