Posterous Groups makes email the core of the product. You can do everything via email including creating a group and replying with rich media attachments. There aren't any restrictions on what you can post.

Facebook Groups doesn't work well as a mobile experience. It's important for me to be able to post and consume content from my iphone. This works well in email and using the Posterous iPhone app.

While Facebook does have a large user base, there will always be people who aren't on the service or don't sign in to it regularly. We're firm believers that email is the best way to reach people.

We've made it seamless to get non Posterous users to understand how a group works and how they should participate. Give it a shot and please send feedback our way.

Thanks!

We got a volunteer who said she'd help moderate, but then all she wanted to do was post links on Facebook that pointed to WC stories. I explained to her that we were looking for her to help edit stories, post cool stuff, and participate in discussions and she kept asking if we could just move it all over to our Facebook page. I tried a few times to explain why that was counterproductive but she kept giving me blank looks. I asked her what web sites she visits, and she said, Facebook, Amazon, and Apple. That's it. Turns out, she doesn't even visit political blogs, she just visits their Facebook pages and talks about their content there. Unreal.

She's still posting her Facebook links, but the idea of her hanging out anywhere outside her "big 3" is just anathema to her. She's got X bandwidth for web sites, and it's all being consumed.

I think Facebook definitely has the stronghold with familiarity, though. I'd expect their groups features to expand dramatically in 2011.

I'm not sure about the media thing, though it's not really practical for video to attach the media...surely posterous doesn't do that either.

For example, while Facebook Groups does allow commenting by email, if you attach a picture to a reply, it doesn't appear in the group.

Secondly, I don't see many small businesses or even teams within large companies using Facebook Groups to collaborate.

Not sure if that's relevant, since I don't see any way that they start using Posterous for that.

Whatever, I'm just throwing out my opinion that this doesn't seem like a big deal in Dec 2010. Maybe the ability to attach inline pictures will make all the difference, though.

Many businesses also use Yahoo Groups or Google Groups today for email lists. Yet those products are pretty lacking.

We think there's a real need for a modern email list solution and we're confident we can get users from individuals to businesses to bring their lists to Posterous.