REGARDING THE CONTENT SOURCE OPTION:
The content source box is for sourcing your content from outside of tumblr, or overriding the source to the content’s real creator.
You don’t need to source your own blog here. Tumblr will automatically source your link in reblogs.
If you insist on having a click-through link, you can still do that without using the content source box.
When you use content source and put in yoururl.tumblr.com it will direct people to your main page, and not that specific post, which sucks if people just want to see that post on your page, like if they wan’t to reblog it directly from you.
Using the content source box does not make your post “better” or give you “more credit”. Rule of thumb: if you’re the creator of the post/content, you don’t need to enter anything here.
Old news/reminder: when you use a click-through link, it prevents people from being able to click to see fullsize/hi-res images, so thats cool for small images and gifs, but otherwise if you’re putting click-through links back to yourself on large images, then obviously you care more about your traffic and new followers than you do your content and current followers.
What do you think?