Tumblr announced the launch of a new feature called "Highlighted Posts". A post on the Tumblr Staff Blog explains:
Every now and then, a post comes along that’s meant for big things. It could be pulling the wraps off your new project, promoting your next show, raising awareness for a cause, or just sharing a truly incredible photo.
Today you’ll have a new option to Highlight those extra-important posts. For one dollar, your post will stand out in the Dashboard with a customizable sticker to make sure your followers take notice!
Interesting monetization strategy. A buck for a customizable sticker.
I'm not sure how much this will help items stand out. Tumblr already gives you options to create very visual posts, with images (including animated gifs) and videos.
I guess anything you can do to stand out will help. Tumblr is getting 15 billion pageviews a month these days, so you might as well do what you can, if it's worth it to you.
Here are the options Tumblr gives you: