The infamous term 'blog' has a new competitor. Similarly to how 'facial tissues' became 'Kleenex' or 'copies' became 'Xeroxes', 'blog' is set to become known as 'Tumblr' if the current trends, available here, continue. Usually the names of companies become synonymous with what they do only after they have achieved a majority usage.
This achievement would confirm that Tumblr really has established itself as the most popular blogging platform on the web. Currently, the term 'blog' is ahead of 'Tumblr' but XKCD blogger Randall Munroe believes that 'Tumblr' will see more Google searches by October 12 this year. If you want traffic to your blog, your best bet is to publish it on Tumblr.
As for Tumblr itself, it is looking to capitalize on its explosion of popularity. Tumblr has reiterated its commitment to keep ads off of the site, instead moving towards other forms of revenue generation. David Karp calls the $1 post highlighting "one of [Tumblr's] most successful revenue-generating features."