What’s Next for Posterous: Geo, Groups, Premium

Posterous, the email-based blogging platform, emphasizes simplicity and ease of use, yet it keeps adding new features. Unlike, say, Twitter, the company isn’t so dogmatic about simplicity that it forgoes functionality like media hosting and mobile clients. Of course, there are other differences between Posterous and Twitter: Posterous hasn’t experienced the same meteoric growth in usage and hasn’t fostered a developer community to fill in all its gaps.

In reality, said Posterous CEO Sachin Agarwal in an interview today, “We are on the WordPress* end of the spectrum, but people think we’re micro-blogging because we’re so simple.” As Posterous grows and becomes more full-featured, Agarwal and co-founder Garry Tan say they will never lose email posting as a core function, and will always try to build experiences that mimic and integrate with familiar interfaces. The company has some new features in the works: increased support for groups, premium accounts for businesses, proximity-based geoblogs, and a better bookmarklet to bring in outside content.

Groups. Posterous is increasingly used as a group communication tool, where users send messages to Posterous like they would a group email list or a Yahoo (s YHOO) Group. Other group members can sign up to receive all posts by email, so the blog itself is essentially a public or private archive. The difference is, the blog format is a good way to consume and search, and Posterous is much better than email at handling media. As compared to the new Facebook Groups, anyone can participate without even creating a Posterous account.

For example, the TED Conference’s Fellows program has 150-200 people communicating with each other through a Posterous group, Agarwal said. Today, 15 percent of Posterous sites are multi-contributor, but the company thinks that number will rise as it adds new tools like automatic group creation when you cc: Posterous on an email to multiple recipients.

Premium Accounts. To date, Posterous hasn’t made any money, but it plans to start pulling its weight. In the next few weeks, it will be beta-testing Google (s GOOG) AdSense revenue share with some of its celebrity users. (It won’t name names, but folks like Ashton Kutcher use Posterous to host their photos uploaded through Twitter clients.) Early next year, Posterous plans to roll out subscription accounts for small and medium business owners who want to use the service to manage their social media presences. Agarwal said many real estate agents already use the service today to syndicate content to their Twitter, Facebook and other online presences. This use case sounds kind of similar to tools like HootSuite.

Geoblogs. At Blog World Expo this past week, Posterous set up a group blog. Anyone who loaded up the Posterous iPhone (s aapl) app in the vicinity of the Mandalay Bay Convention Center was invited to contribute to a Posterous blog dedicated to the show. The company expects to use these pop-up proximity blogs around additional events, and for other purposes.

A Better Bookmarklet. This sounds a bit dangerous as far as plagiarism goes, but Posterous will be updating its bookmarklet tool so users can grab articles and videos by just selecting them and clicking. The idea is to make it even easier to add new content. Today, 50 percent of Posterous posts contain media other than text, and that portion is rising.

Posterous has just 4.4 million monthly visitors (7.1 including custom domains), according to Quantcast, compared to 30.9 million for rival Tumblr (44.2 including custom domains). It’s possible that’s an undercount of actual usage due to users who interact with the service over email, but unfortunately, Posterous doesn’t provide user or site numbers to make a more appropriate comparison. The company, which has 10 employees, has raised about $5 million in funding.

Automattic, maker of WordPress.com, is backed by True Ventures, a venture capital firm that is an investor in the parent company of this blog, Giga Omni Media. Om Malik, founder of Giga Omni Media, is also a venture partner at True.

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