Richard McManus shows the numbers for Tumblr and Wordpress. Tumblr is growing much, much faster than Wordpress, and then tries to explain it:
The two services offer different things, so this is somewhat of an apples and oranges comparison. Wordpress.com is a fully-fledged hosted blogging platform, while Tumblr is a light blogging and curation service. I myself use both products. However, both are blogging services and so it’s worth comparing the statistics.
At the end of last year we estimated that Wordpress.com was larger than Tumblr in terms of unique visitors and number of bloggers. However we noted that Tumblr had about twice the number of page views per month.
On the page view front at least, Tumblr has exploded in recent months. Quantcast puts it at 12 billion per month currently, compared to 1.4B for Wordpress.com. So Tumblr now gets 8.5 times more page views per month than Wordpress.com (at least according to Quantcast, which in my experience tends to be the most accurate public web statistics tool).
People continue to skin this cat the wrong way.
If you pretend that there are two neatly discretely markets, one which is ‘light blogging’ or ‘microblogging’ and the other is ‘full-fledged blogging’, then you can try to make an apples and oranges argument.
However, if you look at this in terms of the spreading of the social stream metaphor it looks completely different. Then it looks like people are simply adopting the Tumblr social stream experience, and defecting from the not-particularly social, old school blogging experience of Wordpress.
I create a great deal of long-format writing here at Tumblr, and it’s ‘fully featured’ enough for that. So Tumblr isn’t something less that Wordpress. I haven’t given up something that Wordpress offers to blog here. On the contrary: the experience is richer, and people enjoy the social dimension of Tumblr more (see this for a description of the social dimension, if you don’t have a Tumblr account).
Wordpress may still have time to go social, but I am wagering that they will a/ wait too long and b/ sell out to someone like Google or Microsoft.
Also, Tumblr could destabilize Wordpress and other conventional blogging tools by allowing Tumblr users to follow external blogs, pulling that content into the social stream via RSS or other mechanisms. Then I wouldn’t even leave the comfort of the Tumbrl stream to read Mashable or other ‘fully featured’ blogs.