Oh No, They Didn't? Tumblr Launches a "TumbleUpon" Toolbar.

What is it with all the toolbar copycat craziness lately. First, there was Digg going after StumbleUpon with the Diggbar. Then StumbleUpon, which already had a toolbar, introduced a new toolbar/URL shortening service called Su.pr.

Now, micro-blogging service Tumblr is getting in on the act with its own toolbar which it is calling TumbleUpon. Could they try to be more blatant in ripping off StumbleUpon? The toolbar has a random Stumble-like shuffle button which randomly takes you through different Tumblogs in a similar way that StumbleUpon’s toolbars do. On the right there is a heart button if you want to “like” a page, a reblog button and a button that takes you to your own Tumblr dashboard.

StumbleUpon’s Su.pr toolbar, in comparison, also has a random shuffle button for discovering pages Websites other people have Stumbled, and a “like” button. But Su.pr is a URL shortener with powerful analytics on the backend, while TumbleUpon is not. It is just a discovery tool which surfaces other Tumblogs of people who have overlapping “likes.”

So is this a joke? Yes, and no. Tumblr founder David Karp tells us:

It was really an experiment to see how a tool like StumbleUpon would work for Tumblr content. Based on the feedback, it seems to be doing a pretty good job. We really like that it’s the first Tumblr discovery tool that shows off all of the pretty user created themes while exploring content. . . .

We might wind up changing the name when we start promoting it in the Dashboard :)

In a blog post today, Karp also shares some growth stats. He claims that in July, 2009, Tumblr had 50 million visitors, 255 million impressions, 650,000 new posts per day, and 5,000 new users per day.

Tumblr is definitely growing, but comScore estimates a much smaller number of users: only 3.9 million uniques worldwide in June, 2009 and 68 million pageviews. That is a 3X increase in unique visitors over a year ago and a 12X increase in pageviews, but a far cry from the numbers Karp is putting out.

I asked Karp what could explain this disparity. He pointed out that 15 percent of Tumblr’s blogs are on custom domains, and that the 50 million number is for visitors per Google Analytics. The same person can be a visitor more than once. Google counts 20 million unique visitors, and Quantcast counts 13 million worldwide. The site is verified by Quantcast, so I’d go with that number. Any way you count it, though, the service is showing strong growth.

But really, TumbleUpon?