Social fads: Is Tumblr the new Twitter?

The singer and guitarist John Mayer, whose prolific posts on Twitter drew nearly four million followers, shocked fans in mid-September by closing his account.

But Mr. Mayer hasn't gone away. He's switched from Twitter to Tumblr,  a free blogging service that has become a hit among Internet enthusiasts. Tumblr, based in New York, says it is drawing 30,000 new members a day. Mr. Mayer, whose heavy Twitter use was said to have upset his girlfriends, posted that "I have an even larger Tumblr addiction."

The allure of Tumblr and a similar service called Posterous is in their social features and their simplicity. They are only slightly more complicated than Twitter to figure out. Yet they allow you to go well beyond 140 characters of text per post, and to include photos, videos and excerpts from other users' posts. Mr. Mayer, for example, used Tumblr to share a touching fan letter.

Tumblr's ad hoc community of users includes Robert Reich, the former labor secretary, who is now a professor of public policy at the University of California, Berkeley. "Tumblr is incredibly easy to use, wonderful to navigate," Mr. Reich said in an e-mail. His Web site, robertreich.org, is actually a Tumblr blog, or "a Tumblr" or "tumblelog" in online jargon.

But the undisputed king of Tumblr is Anthony De Rosa, who has collected nearly 11,000 followers at his SoupSoup page. Mr. De Rosa, a 34-year-old resident of Hoboken, N.J., posts a hard-to-categorize jumble of other people's blog posts, photos and videos he finds interesting. A picture of Lady Gaga before she became famous. A news item about Internet wiretaps. A parody of bad science reporting. You could easily imagine Stephen Colbert pawing through SoupSoup for joke fodder.

Mr. De Rosa said in an e-mail that when he started using Tumblr in 2007, he saw it as little more than a way to upload photos from his phone.

"Not long after that, I discovered following other people on Tumblr, which means you get all their posts sent to you in your Tumblr dashboard," he said. "And reblogging, which allows you to take posts from other Tumblrs and place them on your own, usually adding your own commentary on the post. It didn't take long for it to occur to me that there was a lot of depth that other platforms, like WordPress, were lacking."

Well-known publications including Newsweek, The Atlantic and Politico have set up their own Tumblrs.

Getting started with Tumblr is easy and quick. As Mr. Mayer wrote, it "takes all of 25 seconds to sign up" and begin posting. Go to Tumblr.com and fill in the three boxes on the home page: e-mail address, password and an address for your Tumblr, like Mr. Mayer's jhnmyr.tumblr.com. Type in the gibberish "captcha" code displayed on screen to prove you're a human and not a spamming robot. You're in.

The first time you log in, Tumblr will also prompt you to upload a profile photo, and will suggest some other Tumblr users to follow. Don't think too hard; just follow the easy instructions.

Tumblr's dashboard has the friendliness and simplicity of a Fisher-Price toy. There are seven big buttons at the top for different kinds of posts: text, photo, quote, link, chat, audio and video. Click one of these, and Tumblr will present an input form optimized for that post type.

Link, for example, contains only two text input boxes: one for the link address, another to give your post a title. There's a third box you can open to add some descriptive text about the link, but the genius of Tumblr is that by default, this box is closed. You're not under any pressure to write something clever.

Click Publish, and the post is live. If you are logged into Tumblr and viewing someone else's Tumblr post, a Reblog button appears at the top right of the page. Click that, and Tumblr will jump to another custom form, with the correct title, HTML code and attribution to the other Tumblr already filled in for you.

Tumblr's president, John Maloney, said the site's premise was that much of what people wanted to share online was not content they had created, but snippets from somewhere else: a photo, a quote, a link, a video. By simplifying and customizing the input page for each type of post, Tumblr makes this sort of reblogging much less daunting.

To make your Tumblr more personal, you can choose a custom visual theme. Go to your dashboard and click the Customize link on the right-hand side of the page. On the customization page, click Theme at the upper left. Tumblr will pop up a list of 89 different themes. Click one, and it shows you what your site will look like, without making you commit to the theme. The Atlantic has made its professionally designed theme available for everyone.

Most themes are free, but some, like the Scaffold theme Mr. Mayer uses, are on sale for prices that range from $9 to $49. To apply Scaffold to your site, click it and then look for the Purchase Theme button at the upper right of the page. Click that, and a small window pops up to accept your credit card number. For $9, Scaffold makes your Tumblr look as if you hired your own designer.

If blogging on Tumblr still feels like too much work, you can literally phone it in to Posterous, another free blogging service. To begin, send an e-mail to post@posterous.com from your smartphone. Posterous will automatically set up a personal account for you and reply to your e-mail with its Web address. No login or password is required. Instead, everything you send in from the same e-mail account -- text, photos, video -- will be posted for you in a user-friendly layout.

You can attach as many photos as you want to one message, up to 100 megabytes at a time. Posterous will take an e-mail with multiple pictures attached and create a photo album. Don't worry about file formats. Posterous can automatically embed videos from 50 sites like FunnyOrDie.com, documents posted on Scribd and interactive Google maps. Mail the Web address to Posterous and it will create a post out of the content it finds there.

The service's winning feature is that you never need to log in to your Posterous dashboard to use the site. All you have to do is alert friends and family to bookmark your Posterous address to see your latest updates.

Both Tumblr and Posterous let you send notifications of your updates to Twitter, Facebook  and other social networks with a little configuration work. But what if you want to become a popular blogger read by thousands? Brian Solis, a social media marketing consultant, said that SoupSoup's success is built upon Mr. De Rosa's heavy reblogging, plus his own comments.

"You have to follow to be followed," he said. "You have to comment and respond to earn support."

That's the one thing no site can automate: your own words.